ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
513 
soul of the expedition, to whom science owes a great debt of gratitude 
for his never-ceasing care and toil. The modest language which 
Dr. Murray uses with regard to the most important work of his life is 
quoted with high appreciation. The fact that, of the fifty volumes of 
the ‘Challenger’ reports, more than nine-tenths are purely biological 
leads us naturally to suppose that the future of oceanography will lie 
with biology and with its ways and means for increasing our knowledge. 
It would be of the highest advantage if one nation, or an international 
combination, would present biology and oceanography with a steamer 
expressly built for purposes of such research as the ‘ Challenger ’ per- 
formed, and it is at any rate clear that a scheme of this kind is the best 
way of enlarging our knowledge. In conclusion, Dr. Dohrn ventures 
to utter the thanks of science to the officers and men of the ‘ Challenger,’ 
to the Admiralty, to the British Government and Parliament, and to the 
whole British nation for having set the example to the world of one of 
the grandest and most successful scientific expeditions that ever has 
been, and most likely for considerable time to come will be, started. 
Dr. Dohrn’s enthusiastic article ought to give a new impetus to the 
study of the biology of the great oceans. 
Coelom, Genital Ducts, and Nephridia.* — Mr. E. S. Goodrich calls 
attention to a theory of the homology of the coelom which, though 
gradually gaining ground abroad, has not, he thinks, received in this 
country the notice which it deserves. This theory is, that the cavity 
which we know as the coelom in the higher Coelomata, is represented by 
that of the genital follicles in the lower types of that grade ; in fact, 
Hatschek’s suggestion has now become a well-established theory. 
Although the theory has been, at all events, partially adopted by other 
writers, no one, so far as Mr. Goodrich is aware, has pushed it to its 
logical conclusions, and applied it to all the groups of Coelomata. This 
is what he attempts to do in the present paper. We are led, it seems, 
to the conclusion that we have been confusing two organs of totally 
different origin under the one name nephridium ; the one organ is the 
true nephridium, the other the morphological representative of the 
genital duct, which may be called the peritoneal funnel. It seems that, 
while both are present in the adult of many Worms, Rotifers, and 
Endoproctous Bryozoa, there are no certain traces of true nephridia in 
the Ectoproctous Bryozoa, the Mollusca, the Arthropoda, the Echino- 
derma, or the Yertebrata. In these latter groups, the peritoneal funnels, 
or primitive genital ducts, take on the excretory functions of the 
nephridia • which they supersede. In briefly reviewing the various 
classes of the Coelomata, the author endeavours to show that the two 
kinds of organ can always be distinguished. The nephridium, primi- 
tively excretory in function, is developed centripetally and quite inde- 
pendent of the coelom, possesses a lumen which is developed as the 
hollowing out of the nephridial cells, and is generally of an intracellular 
character, is closed within, and may secondarily acquire an internal 
opening either into a blood space or into the coelom. The second kind 
of organ, the peritoneal funnel, is invariably developed centrifugally as 
an outgrowth from the coelomic epithelium or wall of the genital follicle, 
* Quart. Journ. Micr. Sci., xxxvii. (1895) pp. 477-510 (2 pis.). 
