ZOOLOGY AND BOTANY. MICROSCOPY, ETC. 579 



conclusion that the nucleus has an active role in the process of secre- 

 tion. Thus he emphasises the fact that vilirubin appears in the form of 

 crystals in the nuclear parenchyma. 



Nervous System of Anodonta, Distaplia, and Synapta.* — A. 

 Bochenek, using Apathy's gold method, has made a histological study 

 of the nerve-cells and glia-cells in these animals, with especial reference 

 to the neuro-fibrils. 



Study of Pierasfer.f — L. Bykowski and J. Nusbaum continue their 

 study of this interesting fish, describing the minute structure of the skin 

 and integumentary sense-organs, and also the vexillum and caudal ap- 

 pendage (of the larval forms) which undergo a peculiar degeneration 

 and disappear. 



c General. 



Intra-Organismal Selection.}: — Cecil B. Crampton seeks to apply, 

 as Rous and others have done, the selection-idea to intra-organismal 

 conditions, to the inter-relations of cells and parts of cells. " If we 

 have two sets of qualities derived from the two parents, and if, as 

 modern research indicates, these qualities are apposed in sexual trans- 

 mission, there is a possible mechanism by which only those properties in 

 the germ-cell shall be transmitted, which are the couples of those pro- 

 perties in the body which have been successful in adaptation to their 

 surroundings. These latter must, in the dual personality, either destroy 

 or render latent the corresponding properties derived from the other 

 parental gamete. It might be that the one is rendered latent, and the 

 other dominates the metabolism of the cell, and as to which becomes 

 dominant would depend largely on the external environment in the 

 delicate adjustment of the organism to the surroundings. ... It may be 

 that there is perpetual struggle for dominance in the metabolism of the 

 cell ; that the environment throws the balance of the dominance to one 

 side or the other ; that products of the dominant activity in the form of 

 enzymes or the like render the other half latent and gradually suppress 

 it ; that such emanations may react upon the germ-cells ; and that heredity 

 would follow slowly upon change in the individual under changed con- 

 ditions of life." The hypothesis advanced in this paper is but ;i 

 carrying of natural selection into the tissue-cells as individuals, which 

 work in a kind of symbiosis in their complex relations to one another. 



Comparative Anatomy and Physiology of the Eye.§ — Kalt is the 

 author of an encyclopaedic account of the comparative anatomy and 

 physiology of the optic apparatus both in Invertebrates and in Verte- 

 brates. 



Origin of Lungs.|| — A. Goette returns to the question of the homo- 

 logy between lungs and swim-bladder, and adheres to the view which 



* Bull. Internat. Acad. Sci. Cracovie, 1905, pp. 205-20 (1 pi. and 2 figs.), 

 t Tom. cit., pp. 169-98 (15 figs.). 



j Proo. E. Phys. Soc. Edinbuigh, xvi. (1905) pp. 62-75. 



§ Encyclopedie frai^aise d'Ophtalmologie, Paris, 1905. See Joura. de l'Auat. 

 Physiol., xli. (1905) pp. 441-3. 



H Zool. Jahrb., xxi. (1904) pp. 141-60 (6 figs.). 



