December 22, 1923] 



NA TURE 



905 



complete castration and suffered from want of vigour 

 and general apathy. Lichtenstern then engrafted an 

 undescended testicle from another individual, and as 

 a consequence the s\Tnptoms of castration disappeared 

 and the man became normal. Two and a half years 

 later he was still normal, having been married fifteen 

 months. Further cases of testicular transplantation in 

 men are recorded by Lichtenstern as well as by Kreuter 

 and Miihsam, the operation being performed for 

 eunuchoidism and homosexuality, as well as for debility 

 and impotence, and successful results are claimed. In 

 none of these cases does there appear to be definite 

 evidence as to the fate of the graft, but it would appear 

 almost certain that it must have persisted for some 

 time. 



Voronoff, whose work on the so-called " monkey 

 gland " has attracted so much attention, began his 

 experiments on the testicular graft at the College de 

 France in 191 7. His earlier work was upon sheep and 

 goats, in which he grafted young testes into old animals 

 and into animals castrated before puberty. The best 

 results were obtained by grafting the testes into the 

 scrotal sacs, or in the case of aged animals, upon the 

 testes already present. Retterer and Voronoff, in a 

 paper published last summer, tell us that some of these 

 animals are still under observation at the Laboratory 

 of Experimental Surgery of the College and that they 

 continue to display sexual vigour and ability to copu- 

 late. The success attending these experiments led 

 Voronoff to attempt testicular transplantation upon 

 aged men. In connexion with this work, two points 

 are strongly emphasised ; first, the advantage of 

 making the graft in a suitable position and preferably 

 the natural position of the organ ; and secondly, the 

 importance of biological affinity between the individual 

 from which the testis is taken and the recipient of the 

 graft ; consequently, in carrying out testicular trans- 

 plantation from animals to men, Voronoff selected the 

 chimpanzee as the most suitable animal from which to 

 obtain the graft, since of all the anthropoid apes this 

 species is believed to be the nearest akin to man. The 

 result of the operation in many instances is claimed to 

 be entirely successful. The walls of the arteries are 

 said to have become softened and the capacity for 

 work increased, and, in short, a complete restoration 

 of mental and muscular vigour is stated to have been 

 attained. In the majority of men so operated upon 

 sexual potency also is said to have been revived. 



In some of Voronoff's experiments there is definite 

 evidence concerning the persistence of the graft, and 

 Retterer and Voronoff have described microscopic 

 sections of graft tissue after several months of trans- 

 plantation. Thus the figure of a section of a goat's 

 * stis a year after grafting shows cells which might 



reasonably be supposed to have had an internally 

 secreting function, though the tissue as a whole had 

 undergone considerable degeneration and neither sper- 

 matozoa nor interstitial cells can be detected. The 

 authors state that the condition of the transplanted 

 chimpanzee's testis is similar, but they do not appear 

 to have recorded the duration of the graft. On the 

 other hand, Thorek, an American surgeon, who has 

 recently confirmed Voronoff in regard to the persistence 

 and efficacy of the chimpanzee graft when made upon 

 man, has described and supplied photographs of sections 

 of such grafts when removed four months after trans- 

 plantation, and these show an abundance of secretor\- 

 cells and every evidence of active life, though the semini- 

 ferous tubules had undergone incomplete regression^ 

 The good results are attributed to a new technique 

 whereby the vascularisation of the graft was greatly 

 im proved. 



There is one point of importance on which Retterer 

 and Voronoff differ from most physiologists, and this 

 relates to the elements which are responsible for pro- 

 ducing the internal testicular secretion. The bulk of 

 the experimental evidence is strongly in favour of the 

 view that the testicular hormone is elaborated by the 

 interseminiferous or interstitial cells, and Steinach, who 

 has called this tissue the " puberty gland," attributes 

 the supposed rejuvenating effects of vasectomy to the 

 hypertrophy of this gland, pointing out that the sper- 

 matogenetic tissue after this operation undergoes de- 

 generation as noted by former observers. According 

 to the French investigators, however, the testicular 

 graft does not contain interstitial cells, the rejuvenating 

 function being due to the epithelial cells which continue 

 to discharge the problematical secretion into the circula- 

 tion notwithstanding the fact that they become con- 

 verted by poverty of nutrition into " young connective 

 tissue." On the other hand, in Thorek's preparations, 

 the interstitial cells have proliferated and appear to 

 have been functionally active. 



In conclusion, it must be emphasised that the work 

 is as yet in the experimental stage. In many of the 

 cases recorded the effects of " suggestion " are not 

 satisfactorily excluded, and the evidence as to the per- 

 sistence of a functional graft is still meagre. That the 

 histological results are conflicting and that those of 

 Voronoff are contrary to the usual view as to the source 

 of origin of the hormone, are valid reasons for reserving 

 judgment. Nevertheless, it must be pointed out that 

 the accumulation of evidence in support of the conten- 

 tion that a testicular graft obtained from another in- 

 dividual, and even from another species, may exert a 

 definite physiological influence upon the recipient, is 

 considerably greater than many men of science have 

 so far been disposed to admit. 



Some Aspects of the Physical Chemistry of Interfaces.^ 

 By Prof. F. G. Do s nan. (I.E., F.R.S. 



TET us now inquire how far the phenomena which 

 -^ are characteristic of a gas-liquid interface occur 

 o at the interface between two immiscible or partially 

 iiiiscible liquids. Many years ago it was shown by 

 Gad and by Quincke that a fatty oil (such as olive oil) 



' Conlinu«l from p. 870. 



NO. 2825, VOL. I 12] 



is very readily dispersed in the form of an emulsion 

 by a dilute solution of caustic soda. Some experiments 

 which I once made showed that a neutral hydrocarbon 

 oil could be similarly emulsified in a dilute aqueous 

 solution of alkali if one of the higher fatty acids was 

 dissolved in it, whilst the lower fatty acids do not 



