GENERATIVE ORGANS OF SOME CARTILAGINOUS FISHES. 505 
traces of embryonic growth, as from the experience of the Maltese fishermen, 
who, in opening hundreds of the species, I have been assured, have never found 
a young fish included. 
The branchial filaments of the embryo of the cartilaginous fish have commonly 
been considered as concerned solely in aérating the blood of the young fish. 
Have they not another use also ?—are they not concerned, in a formative way, 
in promoting the growth of the part to which they belong? The circumstances 
that they are absorbed about the time that the gills become covered,—i.¢., cease 
to be naked,—and that they are not always restricted to the branchia, seem to 
favour an affirmative answer. 
As to the use of the anal appendages of the male cartilaginous fishes, respect- 
ing which there has been so much difference of opinion amongst naturalists,— 
some, as RoNDELET, WILLOUGHBY, Ray, ARTEDI, Macri, DE BLAINVILLE, following 
ARISTOTLE in the opinion that they are penes, organs of intromission ; others, as 
Biocu, Home, Cuvier, and most recent writers, maintaining that they are merely 
holders, “ claspers,” and in the generative act employed solely to embrace and 
retain the female,—I have been led to prefer the older view mainly from the 
consideration of the structure of the parts, seemingly so ill adapted for the use 
last referred to, especially keeping in mind the glands with which they are 
furnished. Which of the two hypotheses is the correct one, can only be deter- 
mined by further and careful observation. The fact I have mentioned under 
the head of S. centrina must be admitted, I think, to favour most the old opinion. 
Theoretical arguments might be used in support of the same; but these, at best, 
cannot compel conviction.* 
Lesketu How, AMBLESIDE, 
Sept. 22, 1860. 
* Macri, in Atti della Reale Accademia Scienze (of Naples), vol. 1, uses a very ingenious 
argument of the kind above alluded to: ‘‘ In natura osservi una legge costante ed invariabile, stabi- 
lata dall’? omnipotente, che quando gli animali maschi son corredati d’una sola verga, le lor femmine 
hanno eziando una sola vulva ed un sol utero. KE all’ opposto, dove le medesime son provvedute di 
due vulve, o d’una bifurea, e die due uteri, o d’un uteri bifido, posseggno i maschi o una verga bifida 
o un doppio membro generatore ” (p. 83). 
