532 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Relation between Thymus and Generative Organs.*— E. T. 

 Hainan and F. H. A. Marshall have made a series of experiments on 

 guinea-pigs with a view to investigating the relation between the thymus 

 and the generative organs, and the influence of these organs on growth. 

 They find that removal of the thymus in young guinea-pigs does not 

 alter the growth. Removal of the testes and epididymes in young- 

 guinea-pigs does not affect the growth of the animals before sexual 

 maturity, nor does the simultaneous removal of the thymus and testes. 

 Thymectomy is not followed by hypertrophy of the testes. Castration 

 leads to an arrested atrophy and subsequent hypertrophy of the thymus. 

 This agrees with the conclusion reached by other investigators. There 

 is no evidence of a compensatory mechanism between the testes and 

 the thymus. 



As some of the conclusions differ from those reached by Noel Paton 

 in his work on the same subject, the figures on which they are based 

 have been statistically treated by G. Udny Yule in an appendix to the 

 paper. 



Rectal Gland of Elasmoranchs and Appendix vermiformis in 

 Man.f— Arturo Morgera calls attention to the results of an investigation, 

 published in 1909,| in which he maintained that the rectal gland of 

 Elasmobranchs was homologous with the appendix vermiformis, and was 

 also analogous, having an " ectoproctal " function, i.e. conducing to the 

 expulsion of the undigested material. He made experiments showing 

 the effect of the secretion of the gland when introduced into the intes- 

 tine. The same view has been recently maintained, he points out, by 

 R. Robinson, § who appears to have overlooked Morgera's work. 



Fauna of a Coal-pit at Great Depths. ||— James Ritchie reports 

 thirteen species from a Midlothian coal-pit at a depth of 750 feet and a 

 quarter of a mile from the shaft. Most had doubtless come in with the 

 pit-props and the horse-fodder ; and the flies had perhaps been helped 

 by the air-currents. No special modifications, e.g. in colour or in eyes, 

 were observable. The list includes : common mouse ; brown rat ; house 

 sparrow ; the great slug (Limax maximus) ; a small spider, Lessertia 

 dentichelis (an addition to the known fauna of Scotland) ; a " docker " 

 beetle, Quedius mesomelinus, and a larva probably of this species ; 

 another beetle, Thanasimus formicarius, common in the open country on 

 logs of Scotch fir ; two Diptera (Psychoda humeralis and Phora (Aphio- 

 chseta) ruftpes) ; springtails or pit-fleas (Tomocerus minor) in great 

 abundance ; two earthworms (EisenieUa tetrsedra and Helodrilus {Dm- 

 drobsena) rubidus) ; and a Mycetozoon on the pit- frogs {Stremonitis 

 fused). The chief interest of the collection is that it illustrates the 

 incipient stages of a cave fauna. 



* Proc. Roy. Soc, lxxxviii. (1914) pp. 68-89 (5 figs.). 



t Anat. Anzeig., xlv. (1914) pp. 429-30. 



% Boll. Soc. Nat. Napoli, xxiii. (1909) pp. 51-2. 



§ Comptes Rendus, 1913, pp. 790-1. 



|| Scottish Naturalist, 1914, pp. 158-61, 181-8. 



