192 PHOLADID®. 
season, when all nature flags, and takes repose after the 
exhaustions of the summer, and when even the influences of 
the “ ASneadum Genetrix” are softened down, then the 
ovaria and the pyriform virile membranes become obsolete : 
these two very different states may have contributed to pro- 
duce erroneous conclusions. We must, as I have elsewhere 
observed, not forget the precept, 
«« AEtheris et terree genitabile queerere tempus.” 
I do not mention that I have quoted this line a second time, 
as an apology for the repetition; on the contrary, | mean to 
mark the great importance in which it was held by the illus- 
trious author, who has in his work repeatedly used it or its 
equivalent. 
The ovarium of P. dactylus is a conical organ, amalgamated 
with the lower part of the body, having a poimted apex. 
Though I applied the quicksilver, I did not satisfactorily 
make out the oviducts; they do not appear to be at the apex 
of the ovarium, and I am inclined to think that they are 
situate at the junction of the body with that organ. In 
many bivalves it is considered that the ova, on issuing from 
their receptacles, are at once committed to the protection of 
nature. This idea is mainly correct, but in certain species, 
for example in the Kelliade, &c., the ova, after fecundation 
and exclusion from the ovarium, are for some time committed 
to the protection of the parent before final ejection; im 
Anodon and the Mytil, they are transferred to the branchial 
laminz for maturation. In the Pholades, we believe the ova 
pass at once from the ovarium into their native element. 
Since the above observations were written, Messrs. Alder 
and Hancock have dissented from my theory; I replied by 
the following letter :— 
To the Editors of the Annals of Natural History. 
GENTLEMEN, Exmouth, September 1853. 
I request permission to reply to Messrs. Alder and Han- 
cock’s comments in the ‘ Annals of Natural History,’ vol. viii. 
