ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 685 



surfaces of the legs : in descendants who do not follow the hereditary 

 craft the characteristically smooth skin surfaces may be seen. "The 

 absence of hair from the inner side of the leg in jockeys is not difficult 

 to observe, although hard to trace beyond the professional family." We 

 hope Professor Anderson will publish more precise data. 



Form of the Trunk-Myotome.* — J. W. Langelaan describes the 

 form of the trunk-myotome in the lamprey and the dog-fish. His 

 method is based on the dissection of the intersegmental tissue. The 

 trunk-myotome of Pelromyzon fluviatilis is in general a crescent, with 

 the cornua directed towards the head and slightly inclined to each other. 

 In Acanthias vulgaris the form is complicated. It is differentiated into 

 three parts by a process of infolding, the lines of folding being parallel 

 to the sagittal axis of the body. 



Curves of Growth.t — M. Stefanowska has weighed a brood of 

 chickens at regular intervals and has followed them into adult life. 

 The curves of increase in weight are practically the same for the two 

 sexes, but irregularities appeared in the females when egg-laying began. 

 To begin with, the weight increased rapidly with age, but a point of 

 inflection appeared when the cock attained 77 p.c. and the hen 93 p.c. of 

 the maximum. This occurred about midway in the period required to 

 reach the maximum. Thereafter growth in weight became slow and 

 soon became stationary. In general the curves correspond to those 

 obtained for mice and guinea-pigs. Mathematical expressions of the 

 results are given. 



Brain Weight in Vertebrates. $ — Ales Hrdlicka submits a large 

 series of data showing the weight of the brain in proportion to that of 

 the body in a series of mammals and birds. 



Biological Theories. § — Alfonso L. Herrera expounds in a handy 

 volume his personal views in regard to the fundamental problems of 

 biology. His primary proposition is that all the material phenomena 

 of organisms are interpretable in terms of known physico-chemical forces, 

 and he devotes a considerable part of the book to interpretations of 

 protoplasmic structure, cell-division, and the like, in terms of chemistry 

 and physics. Apart from his own particular views, he gives terse accounts 

 of the various important contributions to biological theories, not forget- 

 ting Mendel, and coming down to De Vries. One of the features of 

 the book is the number of clear synoptical tables, showing the phases 

 of opinion on many subjects. It should be very useful to Mexican 

 students. 



Ridges on the Sole and Palm in Primates. |j — Otto Schlagin- 

 hausen has made an elaborate study of the patterns on the plantar 

 surface of lemuroids, monkeys, and man, with some reference also to the 

 palm surface. He discusses the origin of the ridges and their coalescence 



* K. Akad. Wetensch. Amsterdam, Proc. Section of Sciences, vii. (1904) pp. 34-40 

 (1 pi. and 4 figs.). t Cmptes Kendus. cxli. (1905) pp. 269-71. 



% Smithsonian Misc. Coll., iii. (1905) pp. 89-112. 



§ Nociones de Biologia, Mexico, 1904, 251 pp., 84 figs. 



|| Morphol. Jalirb., xxxiii. (1905) pp. 577-671 (76 figs.); xxxiv. (1905) pp. 1-125 

 (194 figs.). 



