ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 637 



marmoratm and Tr. cristatus (sub-species typica and sub-species camifex) 

 in both directions. It seems that Triton Uasii de l'lsle is simply one 

 of such hybrids, and the author indicates that it will prove a useful 

 subject in connection with Mendel's law. 



Bilateral Symmetry in Egg of Necturus.* — A. C. Eycleshymer 

 finds that the primary area of cellular activity is at or near the upper 

 pole, and it determines the position of the future head-end of the 

 embryo. There is an early appearance of a second area of accelerated 

 cell-division, which determines the position of the forthcoming blasto- 

 pore and consequently the posterior end of the embryo. A line passing 

 through the centres of the two areas coincides with the median plane of 

 the future embryo. 



Inheritance of Mental Qualities in Man.f — B. Rawitz discusses 

 this subject. His point of view is that inheritance here is a physio- 

 logical impossibility. Ganglion cells are occupied with specific functions 

 and cannot acquire new qualities. They are without any power of 

 transforming received material so as to influence the molecular structure 

 of sperm and egg. 



b. Histologry. 



Models of Cellular Mitoses.}— M. Hartog has studied the " mag- 

 netic spectrum " obtained in a viscous substance, in order to elucidate 

 the play of forces in mitotic division. 



His mimetic model has proved very suggestive. It is necessary to 

 analyse the karyokinetic forces (which combine to evoke two daughter- 

 nuclei) into at least three sets. First, there are the usual cytoplasmic 

 movements, determining the repulsion of the poles and the elongation. of 

 the spindle, aided perhaps by osmosis, for all the appearances of turgidity 

 are often observed. Second, there is the force w T hich determines the 

 mutual repulsion of the chromosomes, potent even in the still intact 

 nucleus, and perhaps comparable to static electricity. Third, there is 

 the force which has its seat in the kinoplasm, and which produces the 

 chains of force which Hartog calls " mitolcinetic " because of their 

 analogies with magnetism. In all kinetic interpretations of cellular 

 mitoses, it is necessary to keep in mind the distinction between lines of 

 ideal force and chains of material force. 



Comparative Histology of Pancreas.§— Giuseppe Levi has studied 

 in particular the pancreas of Lemur mangos var. rubifrons, in which 

 there is an enormous development ^of the tissue composing the islands 

 of Langerhans. They are not only large, but unusually numerous. 

 There is a poor differentiation of zymogenic tubules in the canalicular 

 system of the pancreas. The author makes a number of comparative 

 notes on the state of the pancreas, and of the islands of Langerhans 

 in particular, in various Mammals. 



The Question of Sinusoids. || — F. T. Lewis seeks to show that there 

 is an essential difference between capillaries and sinusoids, and considers 



* Anat. Anzeig., xxv. (1904) pp. 230-40 (47 figs.), 

 t Biol. Centralbl., xxiv. (1904) pp. 396-408. 

 \ Comptes Rendus, cxxxviii. (1904) pp. 1523-5. 

 § Anat. Anzeig., xxv. (1U04) pp. 289-98 (1 pi.). || Tom. cit., pp. 261-79. 



