348 SUMMARY OF CURRENT RESEARCHES RELATING TO 



in Borne other mammals, the seminal cells disappear from the testes. A- 

 in the cat, there are some refractory oviform cells, but they are notable 

 in repopulate the seminal epithelium. The sterilization can be effected 

 withoui radio-dermitis by taking certain precautions. 



Interstitial Testicular Cells and Secondary Sex Characters. *— 

 L. Mazzetti nasstudied these cells in various Vertebrate types, lie finds 

 thai they arise from a transformation of connective cells between the 

 testicular tubules and in lymphatic lacunas. They do not seem to have 

 any importance, or not more than a minimal importance, in connexion 

 with the development of the secondary sex characters. Tin's is affected, 

 however, by the re-absorption of seminal fluid, seminal cells, and their 

 secreted products. 



Injection of Testis-extract into Hens. f— Geoffrey Smith has found 

 that the injection had an entirely negative effect on the increase of the 

 comb in adult and young hens when compared with the fluctuations of 

 growth observed in control birds. The injections had no observable 

 effect on the health, body-weight, fertility, blood-properties, or any other 

 features, although very large quantities were administered over periods 

 varying from 15 to 75 days. C. E. Walker observed increase of the 

 comb in hens similarly treated, but Smith believes this was not due to 

 the injection. There is " no evidence," he concludes, " that the testis 

 contains an internal secretion which, when injected into the female, can 

 call forth the production of any of the'male secondary sexual characters." 



Mammalian Sports.} — Ernest Warren describes three interesting 

 a 1 (normalities, "striking examples of those curious sports or large varia- 

 tions which occur in a spontaneous manner, and to which we are at 

 present quite unable to assign any definite cause. In all three cases the 

 same abnormality occurred more than once, and the fact of this recur- 

 rence adds considerably to the interest of the observations." The first 

 is a duiker (Cephaloplius grimmi), with a black skin almost devoid of 

 hair. Normally the skin is white with speckled yellow and brown hair, 

 but there is considerable variation in the general colour of the coat. 

 The next offspring by the same parents had also a black skin and had 

 considerably more hair than in the first case. 



Warren describes in the second place a hairless black fox terrier, 

 one of a litter of six or seven, otherwise normal. The hairless dog was 

 paired with a pure white terrier, and two of the litter were hairless. 

 The third sport was a bulldog-headed calf. 



b. Histology. 



Direct Connexion between Muscle-fibrils and Tendon-fibrils.§- 

 Oskar Schnltze refers to the general view that the connexion between 

 muscle and tendon is only by the perimysium, and brings forward 

 evidence to show that it is incorrect. A study of embryo mammals and 

 amphibian larvae has convinced him that each muscle-fibre in a bundle 



* Anat. Anzeig., xxxviii. (1911) pp. 361-87 (14 figs.). 



t Quart. Journ. Micr. Sci, lvi. (1911) pp. 591-612. 



% Ann. Natal Museum, ii. (1910) pp. 235-52 (4 pis.). 



§ Verb. Phys.-Med. Ges. Wurzburg, xli. (1911) No. 2, pp. 33-8 (1 pi.). 



