70 On the SteriliUj of the Tortoheshell Tom Cat 



spermatocytes et enfin les sperniatogonies. Chez un animal sacrifi^ cent 

 deux jours apres le ligature de deux canaux deferents, les tubes 

 testiculaires sont tres reduits de diametre ; ils renferment seulement 

 quelques noyaux de Sertoli sem^s dans un protoplasme indivis....Les 

 cellules interstitielles subsistent entre les tubes s^miniferes. Elles 

 forment, comme dans le testicule normal, des cordons et des trainees 

 situ^s dans les carrefours glandulaires. Elles renferment dans leur 

 cytoplasme des granulations acidophiles et quelques globules de gi-aisse. 

 Le testicule que nousavons ainsi transforme exp6rimentalement ressemble 

 done tout a fait au testicule d'un animal cryptorchide." 



Finally in the same paper by Griffiths as that quoted above, p. 218, 

 it is shown that when a normal testicle is replaced in the abdomen, all 

 care being taken not to injure the organ and to re-establish vascular 

 connexion, it dwindles in size and becomes like a young one which has 

 not developed, there being no trace of spermatogenesis. 



From the facts here described, it is clear that the testis of our 

 tortoiseshell cat resembles rather closely the testis in which sterility is 

 associated with retention within the abdomen. Incidentally, therefore, 

 it throws light on the problem which has given rise to some dispute, as 

 to whether the abnormality of the retained testis is a cause or a 

 consequence of its retention. Some maintain that the testis fails to 

 descend because it is abnormal ; others that the abnormality is due to 

 the failure to descend into the scrotum. The evidence collected by 

 Bellingham Smith in the paper mentioned above, coupled with the 

 results of transplantation experiments, seems to us to point clearly 

 to the conclusion that sterility is a consequence of retention, and this 

 is confirmed by the condition found in the tortoiseshell cat, in which 

 the testes were normal in position although totally sterile. The 

 sterility in this case is clearly due to some other cause, and the question 

 arises whether it is connected with the possession by the animal of 

 a colour found normally only in the female. If so, then other tortoise- 

 shell torn cats should also be sterile, as was suggested in the note 

 referred to at the outset of this paper. We have found that evidence 

 bearing on the question is somewhat difficult to obtain. Mr E. T. Cox, 

 secretary to the "Governing Council of the Cat Fancy," has kindly 

 examined the registers in his keeping, and finds no single case in which 

 a tortoiseshell or tortoiseshell-and-white (tricolour) turn is recorded 

 as a sire. This, though purely negative, is in itself evidence that 

 tortoiseshell toms are not usually fertile, for, although they are un- 

 doubtedly rare, for this very reason they are prized by cat-fanciers, who 



