ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
151 
Endocardiac Epithelium of the Salmon . 1 ' 1 — Dr. B. Noldeke is unable 
to find any evidence that the endothelium of the heart is of purely 
mesodermic origin. On the contrary, it is not possible to define the 
limits of endoderm and mesoderm in the primordium ( Anlage ) of the 
heart. The endoderm certainly has at least a share in forming the 
endocardiac epithelium. 
Theory of Growth and Fertilisation.! — Herr Z. Bernstein starts 
from the idea of an “ U r mater ie” in which growth and reproduction 
coincide. The vicissitudes of environmental conditions induce varia- 
bility ; the struggle for existence begins, and the action of inhibitive 
forces becomes more marked. Sexual reproduction, arising in the 
originally fortuitous fusion of diverse plasma-individuals, implies a 
lessening or assuaging of the aforesaid inhibitive forces, so that the 
growth-tendency has again its opportunity. The sex-elements are 
characteristically different in nature ; indeed, the whole point is in their 
difference. We have not, however, seen the original paper. 
Hairs of Monotremes.^ — Prof. Baldwin Spencer and Miss G. Sweet 
find that the early development of the hair-follicle in monotremes is in 
the form of a solid epidermic downgrowth, not tubular as Poulton sup- 
posed. Their net result, in fact, is that the development of the hairs 
in monotremes is in all essential respects the same as that in other 
mammals. 
Bone-Structure and Inheritance^ — Dr. E. Schmidt discusses the 
minute architecture of the bones, especially at the joints, and comes to 
the conclusion that in the course of function adaptive characteristics are 
acquired whose transmissibility is equally well shown, both by the history 
of the race and by the course of individual development. 
b. Histology. 
Ciliary Movement^ — Dr. K. Peter has made numerous experiments 
on the long ciliated cells from the lining of the gut of the freshwater 
mussel, in order to come to some decision in regard to the “ centre ” for 
the ciliary movement. The most important results are the following. 
(1) Non-nucleated portions of ciliated cells move actively, therefore 
the nucleus is not essential to the play of cilia. 
(2) Isolated cilia without cytoplasm also continue their movements, 
therefore the cytoplasm is not essential. 
(3) The kinetic centre must be in the ciliary structure itself, and 
since those with much damaged basal cones still function, while torn-off 
cilia do not work, the motor centre must be in the “ basal corpuscle.” 
Secretory Phenomena in Poison-Gland of Adder.1T — Herr W. Linde- 
mann has studied the influence of subcutaneous injections of atropin and 
pilocarpin. The former stops the secretion, the latter increases it. The 
appearance of the homologous glands in the grass snake was not changed 
* Zeitschr. wiss. Zook, Ixv. (1899) pp. 517-28 (1 pi.), 
t Arch. Entwickmech., vii. (1898) pp. 511-21. 
X Quart. Journ. Micr. Sci., xli. (1899) pp. 549-88 (3 pis., 6 figs.). 
§ Zeitschr. wiss. Zool., Ixv. (1898) pp. 05-111 (2 pis.). 
Anat. Anzeig., xv. (1899) pp. 271-83 (4 figs.), 
f Arch. Mikr. Anat., liii. (1898) pp. 313-21 (1 pi.). 
