380 Dr. Burnett on the Renal Organs of the Vertebrata. 
This view being correct, we could expect to find Wolffian 
bodies only where there is observed an Allantois, and vice versa. 
Thus, in the Fishes and Amphibian Reptiles, which truly have 
no Allantois, there would be no temporary kidneys or the Wolffian 
bodies; while in the other Vertebrata, which are allantoidian, 
these last wonld be found. TI scarcely need refer further to this 
parallelism as far as regards our doctrine in question.* 
Il. Permanent or true Kidneys. 
These organs being apparently indispensable to the adult econ- 
omy of all the Vertebrata, have a physiological importance of the 
highest character. Althongh the primitive essential type of their 
structure is precisely like that of their temporary analogues just 
described, when present, yet as they are permanent organs ab 
sustain definite relations and connections with various parts of the 
general system, the study of their structure as organs is the more 
complex and interesting. It would be foreign to my subject to 
enter upon the details of the comparative Auatomy of these or- 
gans, describing those variations of external form belonging to 
each type ;+ I shall limit mysclf to those points that bear directly 
upon the subject of development and intimate structure. 
As a leading fact | may mention that the idea or formula of 
the kidney, wherever observed in the vertebrate, is always the 
same; aud thus finding the intimate structure essentially alike 
everywhere, we should naturally infer that there is throughout a 
single and invariable mode of development. This indeed, I have 
found to be the case, as I hope to show in the following details. 
In the Fishes and Amphibian Reptiles, where there are NO 
temporary urinary organs, the earlier phases of development of 
the kidueys seem to bea little less complicated than in the higher 
classes. In fact, the type of structural development here is quite 
allied to that of the Wolffian bodies, and by some anatomists 
I much regret that in preparing this account of the Wolffian bodies, I shoul 
not h ess to the work of Follin, (Recherches sur les co’ ‘ 
Paris, 1850), which I have failed to get on the reputed ground of its being out of Lig 
Considerable reference, ho S to this work, by the copying of 
pag tl ii, p. 761. ut by the figures in question, I can judge nothing of the v. 
e. r * 
Besides the well-known works of Rathke, Meckel, Baer, Jacobson, Valentin, B® 
ee already referred to, see especially for representations of these bodies, hain : 
Bildu gre der Genitalien; his De Glandularum secernent. &e.; 4 
e, Transl. by Jourdan, Paris, 1851, ii, p. 757. " 
Wolffian bodies of Amphibia, see Wittich, loc. cit., Taf. ix, figs. 1, 2, 3, 4 ae ce. 
am 
spect. My obse 
stages of formation of ail the parts, and concerning th 
ed by no investigator. 
+ For full details on this pon eee, with a pate a reference to its literature, oe, 
ee. Anatomy of Siebold and Stannius, transl. &e. by Burnett, ¥ 
> ~- . / o 
