= = = ΥΜΑ, skew-symmetric if and only if dy, ey, and then M2M3 M2MYM3, MзMA YM2. Writing i, j, k for M2, M3, M4, we have the multiplication table of quaternions. Or we may form the matrix M and write X for the sum of the products of the elements of its kth row by $1, §4, and take y 1 (by multiplying x4, 4, X4 by y); we Hence we have again obtained the quatern obtain (11') for c2 = C3 = -1. = ion algebra without assuming the associative law. The case n being investigated in this way by one of my students. 1 Frobenius, Jour. für Math., 84, 1878 (59). = 8 is 2 Dickson, Linear Algebras, "Cambridge Tracts in Mathematics and Mathematical Physics," No. 16, 1914 (10-12). 5 Lagrange, Nouv. Mém. Acad. Roy. Sc. de Berlin, année 1770, Berlin, 1772 (123–133); Oeuvres de Lagrange, 3, 1869 (189). Reproduced in Dickson's History of the Theory of Numbers, II, 1920 (279-281). • Dickson, Trans. Amer. Math. Soc., 13, 1912 (65). 7 Dickson, Annals of Math., 20, 1919 (155-171, 297). 8 Dickson, Comptes Rendus du Congrès Internat. Math., Strasbourg, 1920 (131–146) . NOVOCAINE AS A SUBSTITUTE FOR CURARE1 HARVARD UNIVERSITY Communicated by G. H. Parker, March 3, 1921 Since the recent war, the need of a substitute for the Indian arrow poison, curare, has been keenly felt in many physiological laboratories. While investigating the activity of certain local anesthetics, it was found that novocaine, in its effect upon the neuro-muscular mechanism of frogs, duplicates in many particulars the unique action of curare. If the sciatic nerve of a sciatic-gastrocnemius preparation is bathed in a strong solution of novocaine (2.5 per cent in water or in physiological salt solution) for as long as twenty minutes, no decrease in its conductivity can be observed. However, if the muscle itself is bathed in such a solution (by direct immersion or, "painting" with a camel's hair brush) the power of reacting to nervous stimulation is destroyed within three to five minutes, though ability to respond by contraction to direct electrical stimulation remains unimpaired. Thus, in the action of novocaine there is a complete duplication of the properties originally described by Claude Bernard for curare. Whether novocaine acts directly upon the end-plates of the motor fibers or upon some membrane intermediate between the plates and the 1 Contributions from the Zoölogical Laboratory of the Museum of Comparative Zoology at Harvard College. No. 330. muscle has not been determined. A dye that I have made by linking novocaine with a benzene nucleus was found to be physiologically active, like the 2.5% novocaine, and appears to stain the elements acted upon by the novocaine. When the stain is diazotized directly into the living muscle, by putting the tissue first into novocaine and then into a solution of the staining base, only the muscle nuclei take the stain deeply, the nervous elements of the end-plates as well as the motor fibers remaining uncolored. It seems reasonably certain, therefore, that novocaine acts upon some constituent of the neuro-muscular mechanism beyond the end-plates. The significance of the affinity of the dye for the muscle nuclei is as yet unknown. The object of this note is to direct the attention of physiologists to a convenient substitute for curare. NOTE ON A METHOD OF DETERMINING THE DISTRIBUTION OF PORE SIZES IN A POROUS MATERIAL BY EDWARD W. WASHBURN DEPARTMENT OF CERAMIC ENGINEERING, UNIVERSITY OF ILLINOIS The pressure required to force mercury into a capillary pore of radius, -2 y cos 0 r, is where is the surface tension and the angle of contact. Upon this relation can be based a method for determining the effective pore diameters in a porous material such as charcoal. If pores of various diameters are present, one may determine also the fraction of the total porosity which is due to pores having effective diameters lying between any two stated limits. The procedure would be as follows: The coarsely granular sample of the thoroughly outgassed material is weighed and placed in a steel pressure bomb which is then evacuated until all adsorbed gases are removed. Pure mercury is then admitted to fill the bomb and a series of pressure and volume measurements are made at various pressures up to the highest pressure it is desired to employ. The decrease in volume, AV, accompanying a small pressure increase of Ap, in any part of the range must evidently be due to the filling of pores whose effective radii lie between the limits r and r - ΔΥ, or A blank experiment without the porous material should of course be made in order to correct for the compressibility of the mercury and the expansion of the bomb under pressure. For accurate results the compressibility of the porous material, and the variation of y and with p should also be known. The value of could be determined from an X-ray photograph of a mercury meniscus in a capillary composed of the material under examination, or by the drop-shape method. AN APPARENT CASE OF NON-MENDELIAN INHERITANCE IN DATURA DUE TO A DISEASE BY ALBERT F. BLAKESLEE STATION FOR EXPERIMENTAL EVOLUTION, COLD SPRING HARBOR, N. Y. Communicated by C. B. Davenport, February 26, 1921 In the common Jimson Weed (Datura Stramonium), spiny or armed capsules are dominant to smooth or inermis capsules. A cross between two plants, each homozygous for a single member of this pair of characters will produce spiny fruited offspring in the F1 and a ratio of 3 spiny to 1 smooth plant in the F2 generation. In 1915, the writer found a single inermis plant in a culture where smooth capsules could not have occurred through segregation. It was considered a new inermis mutation and its inheritance was therefore studied in crosses with normals. The new form was called Quercina on account of the increased oak-like dentation of its leaves. The most conspicuous character on the mature plant was the partial or complete suppression of spines on the capsules. An examination of the plants throughout the growing and flowering condition indicated that other parts of the plant were also involved and showed such changes as the slitting of the normally undivided corolla, the absence of pollen, which caused the plant to depend upon outcrossing in order to set seed, and certain other characters associated with less vigorous growth. Later investigation showed that the Quercina character occurred spontaneously in the garden cultures in many ways like a vegetative mutation. In a single year's test, about 1/4 per cent of the normal plants in the field took on the Quercina character by the last of the season. This Quercina character generally shows itself weakly in a single branch and gradually spreads to all the new growth. It occasionally happens on plants which are acquiring the Quercina character that capsules will be found in a transitional condition with their spines only partially reduced. Sometimes some of the valves may be entirely smooth and others on the same capsule fully spined. So far as we can judge from the literature, other investigators who have worked on the Jimson Weed found have Quercina plants in their cultures. They seem not to have noticed, however, any of the distinctive characters other than those shown by the capsules. Naudin1 reports in an F1 between an inermis variety (D. laevis) of D. Stramonium and the armed type, that while most of the plants had spiny fruits, others had fruits with reduced spines. Many of the capsules on three out of the forty plants in this generation were very spiny on part of the surface while totally smooth on the rest. Naudin believed that they united thus by distinct and separate compartments the distinctive traits of the parental types D. laevis and D. Stramonium. He calls this "hybridité disjointe" and cites in this connection the condition in the graft chimera Cytisus Adami. In a series of F2 plants from the same original cross Naudin found 6 individuals out of 38 which again showed more or less well marked his "hybridité disjointe" and which were presumably Quercinas. Godron2 reports finding capsules partly spiny and partly smooth. He objects, however, to Naudin's interpretation that the separation of the fruit into smooth and spiny portions is due to their origin from smooth and spiny parents, since he says that he has found this condition when both parents had spines. 3 Bateson and Saunders, after discussing the intermediate color of the flowers in the F1 between white and purple flowered forms, say: "The occurrence of intermediate forms was also occasionally noticeable in the fruits. Among the large number of capsules examined, there were some of the mosaic type, in which part of the capsule was prickly and the remainder smooth, while others suggesting a blend, were more or less prickly all over, but the prickles were much reduced in size, and often formed mere tubercles. These mosaics occurred as rareties both on prickly individuals and on smooth ones still more rarely." Further evidence pointing to the Quercina nature of these abnormal capsules is given in their following statement: "Such intermediate fruits were most often found towards the end of the flowering season." It may be stated that the writer has grown many thousand plants of the Jimson Weed, including large numbers of individuals that were heterozygous for inermis capsules, but has never observed any except Quercinas which showed a mosaic arrangement of the spines on the fruits, with some valves smooth and others more or less spiny. Despite their misconception of the nature of the phenomenon which they observed, it is highly probable that the investigators mentioned were describing the same type of plant that we have considered under the term Quercina. The Quercina character does not breed true. It is transmitted by seed to about 79 per cent of its offspring when pollinated from normal plants. The remaining 21 per cent normal offspring do not produce Quercina seedlings in the next generation, and hence do not carry the character in a recessive condition. Two plants which were changing over from a normal to a Quercina condition were investigated with regard to the type of offspring obtained from their individual capsules. There seems to be only a rough correspondence between the strength of the Quercina character in the parent and the number of Quercina plants in its offspring. As has been stated already, Quercina flowers are characteristically devoid of pollen. In a few plants, however, which were becoming transformed into Quercinas, pollen was obtained and used in crosses onto normal plants. Quercina offspring were obtained from such crosses showing that the character in question can be transmitted through the male. The non-Mendelian nature of the breeding results with Quercina plants as well as the spontaneous occurrence of the character on branches of normal plants and its spread to the new growth suggested the desirability of attempting to transmit the character by grafting. This attempt was entirely successful and Quercina cions grafted onto normal plants of the Jimson Weed causes the new growth of the stock to take on the appearance of Quercina. There is ample evidence, therefore, to indicate that the cause of the Quercina complex, which by ourselves as well as by earlier investigators had been supposed to be a manifestation of a genetic character, is in fact a disease transmissible by grafting. It has not been found possible to infect plants artificially by rubbing with diseased leaves nor by inoculation of expressed juice from Quercina plants. The profound morphological changes brought about in the leaves and especially in the flowers and fruit are such that Quercina individuals would be considered worthy of specific if not of generic separation if 100 per cent of the seedlings instead of only 79 per cent came true to the Quercina complex. As the facts stand, however, there is much in the behavior of Quercina plants which suggests genetic phenomena. To one who has read the data presented in the foregoing pages, certain similarities may be apparent between the Quercina in the Jimson Weed and rogues in peas investigated by Bateson and Pellew. It will not be desirable, however, to discuss the two forms more in detail until grafting experiments with the rogues in peas have given definite results. A detailed account of the Quercina disease with photographs will appear shortly in the Journal of Genetics. 1 Naudin, Ch., Nouvelles Recherches sur L'Hybridité dans les Végétaux, Nouv.. Arch. Mus., 1, 1865 (41–54). 2 Godron, D. A., Des hybrides et des metis de Datura., Nancy, 1873 (1–75). Bateson, W. and Saunders, E. R., Report to Evolution Committee of the Royal Society, 1, 1902 (21-32). Bateson, W. and Pellew, Caroline, “The Genetics of 'Rogues' among Culinary Peas," Proc. Royal Soc., 91, 1920 (186–195). |