'ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 515 



containing yellow granules, which diminish in numbers from the 

 beginning of the period before sexual maturity. In the adult the gland 

 is of the usual type ; the xanthic granule cells persist in small numbers 

 between the seminiferous tubules. In the aged animal the cells are 

 much smaller ; the peripheral vacuolar zone is reduced or absent in most 

 The secretory activity is diminished and the cells are full of pigment 

 granules. The cryptorchid testis has all the histological alterations of 

 the ectopic testis. The observers are of opinion that the interstitial 

 gland is the only source of the internal secretion of the testicle. 



c. 



General. 



Why is the Human Ear Immobile ? * — Walter Smith argues that 

 Man's loss of mobility in the ear has resulted in a fuller appreciation of 

 the succession of sounds, and thus has been in an important sense a 

 condition of the social, intellectual and aesthetic development which has 

 come with the use of language and music. It is in a high degree 

 probable, though the data are insufficient for conclusive demonstration, 

 that it is to the advantage given in the struggle for existence by the 

 first stages of this development that we are to attribute the permanent 

 alteration in the structure of the external ear. 



Homology of Olecranon and Patella.f — P. le Damany discusses 

 this subject. He is of opinion that the olecranon is anatomically 

 comparable to the humeral trochiter, femoral great trochanter, and 

 great tuberosity of calcaneum. It is an apophysis for muscular insertion. 

 The patella, on the contrary, is a sesamoid bone very like the rest, and 

 often accompanied by many congeners round the knee. 



Defect of Human Hip Joint.t — P. le Damany discusses the peculi- 

 arities of the coxa-femoral articulation, which result from the intra- 

 uterine position, and are perpetuated by the erect habit of locomotion. 

 Its manifestations are the ill-adapted orientation of the femoral neck and 

 cotylus, insufficiency of femoral extension, propulsion of the head by 

 femoral extension, and diminution or suppression of external rotation 

 of the femur. 



Domestication of Zebras. § — R. J. Stordy, in a report to the Secretary 

 of State for Foreign Affairs, gives an account of the proceedings adopted 

 in his experiments on domestication of the zebra. These experiments 

 were highly successful : in some cases the animals were harnessed to 

 vehicles in eight months, and some were ridden within five months 

 from capture. The stallions are to be used by the Indian Government 

 for the production of hybrids. The author is of opinion that, though 

 the wild animal, however well domesticated, may not directly reward 

 experiment, the progeny of semi-domesticated forms will be a suc- 

 cess, and he is confident that in the near future the zebra, which is 

 to-day a wild animal, will be classed as one of our most useful beasts 

 of burden. 



* Popular Science Monthly, July 1904, pp. 228-37. 



+ Travaux Scient. Univ. Kennes, Tom. ii. Fasc. iii. (1903) pp. 849-58. 



X Journ. de l'Anat. et Phys., xl. (1904) pp. 1-21. 



§ Journ. Soc. of Arts, London, lii. (1904) pp. 691-7. 



