ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 165 



66 und 54 kilogrm. "When this is taken into account, the result is- 

 practically equality between the sexes. 



Eighth Cerebral Nerve.* — C. Winkler discusses the central course of 

 the nervus octavus, and its influence on motility. Previous researches 

 have shown tbat the distribution of the eighth nerve is much more 

 complicated than was surmised before, and Ewald has shown that dis- 

 turbances of locomotion in pigeons follow the removal of the labyrinth 

 on one side or on both sides. "Winkler finds that the course of the 

 octavus fibres- and their distribution towards different centres in the 

 medulla oblongata, pons, and mesencephalon is different in detail in 

 pigeon, rabbit, dog, cat, mouse, and man, and that the functional 

 troubles, consequent on section of the octavus in pigeon, rabbit, dog, 

 and cat are also different in detail. The mode of the central distribu- 

 tion of the eighth nerve does not warrant a sharp distinction between 

 that of the N. cochlearis and that of the N. vestibularis. It is necessary 

 to ask whether the cochlear, whose end-organ is endowed with the 

 function of hearing, does not exert a certain influence upon the muscular 

 system, and whether the vestibular, endowed with important significance 

 for motor functions, does not contribute also to the function of hearing. 

 "Winkler thinks that by the octavus-fibres, centres are innervated, whence 

 originate long tracts towards the lateral and anterior columns of the 

 medulla providing the motor centres with fibres, and that even primary 

 octavus fibres, though in a slight degree, follow the same path. We 

 cannot do more than indicate the general nature of this memoir, in 

 which the author seeks to establish a correlation between the distribu- 

 tion of the octavus fibres and the physiological role of the nerve. 



Dentition of Mammals.! — W. Leche continues his important in- 

 vestigations on the ontogeny and phylogeny of mammalian dentitions. 

 In the present instalment he deals with the families Centetidge, Soleno- 

 dontidse, and Chrysochloridas, which he discusses not only as regards 

 their teeth, but in respect to the entirety of their characters. 



His most general result is that the Insectivora should be classified as 

 follows :• — 



I. Sub-order Centetoidea - 



II. Sub-order Brinacoidea 

 III. Sub-order Soricoidea 



[ Family 1. Chrysochloridai. 



„ 2. Centetidas. 



„ 3. Solenodontidse. 



„ 4. Leptictidae. 



„ 5. Erinaceidas. 



| „ 6. Soricidas. 



i „ 7. Talpidae. 



Leche gives some interesting illustrations of convergence, e.g. between 

 Erinacevs and Ericulus, Notoryctes and Chrysochloris ; in the special 

 sesamoid associated with the flexor digitorum profundus in Chrysochloris, 

 compared with Notoryctes and Necrolestes, he finds an illustration of 

 progressive evolution ; in Chrysochloris, again, he sees an example of the 

 preservation of a primitive type by specialisation ; Hemicentetes may be 



* Verb. k. Akad. Wetensch. Amsterdam, xiv. (1907) pp. 1-202 (24 pis.). 

 t Zoologica, xx. Heft 49 (1907) pp. 1-157 (4 pis. and 108 figs.). 



