The Comparative Histology of the Suprarenal Capsules. 295 



4. Dipnoi. 



Until 1896 nothing' had been known of the suprarenals in the 

 Dipnoi, and even now our information is very limited. My own in- 

 vestigations upon preserved specimens yielded entirely negative results, 

 but I stated [116]: — "Nevertheless, from a priori considerations, I be- 

 lieve that adrenals of some sort are almost certainly present in the 

 Dipnoi. These fishes closely approach the Amphibians in many respects 

 and I am persuaded that could one obtain perfectly fresh specimens 

 of large size, suprarenals of a type resembling that of the Amphibians 

 would be found." 



Since the above was written, Pettit [89] has claimed to have 

 found the suprarenal bodies of Protopterus annectens. He says that 

 in general form and relations they resemble those of the Teleostei, 

 while in minute anatomy they are rather like those of the Batrachians. 

 But he gives no histological details and says nothing about cortex 

 and medulla. 



Since this account of Pettit is the only one extant of the suprarenals 

 in Dipnoi, it will be advisable to quote it in full: — 



"Aucun auteur à ma connaissance n'a indique l'existence des 

 capsules surrénales chez les Dipnoïques; c'est là une lacune regrettable 

 que Wiedersheim déplore dans le remarquable chapitre de son Anatomie 

 comparée qui est consacré aux glandes surrénales. 



Grâce à l'extrême amabilité de MM. les professeurs Filhol et 

 Vaillant, j'ai pu constater l'existence de ces organes chez le Protoptère 

 {Protopterus annectens, Owen). 



Sur le spécimen que j'ai disséqué, ces organes étaient représen- 

 tées (PI. III. fig. 8) par deux petites masses de volume inégal qui 



treated elsewhere [116, 111, US, 119, 120, also 20]. It is sufficient here to repeat 

 that there is no anatomical or physiological relationship of any kind between the 

 two (vide supra, pages 4 and 5). 



In the "Comptes Kendus" for last year, No. 25 (Seance du Lundi 21 Juin) 

 is a communication by Huot on the suprarenal bodies of Lophobranchs in which 

 he expresses the opinion that in these fishes the suprarenal capsule has nothing 

 to do with the lymphoid tissue of the kidney. 



In a later communication (Compt. Rend. CXXVI 1. p. 49), Huot says that 

 the suprarenal bodies of Lophobranchs are developed as 2 hollow diverticula from 

 the hinder end of the Wolffian duct. 



