72 CARPENTER, ON THE MICROSCOPE. 
Fucus into several cells capable of impregnation and development* is 
hardly analogous, inasmuch as with the latter process the impregnation 
of the free spore commences and forthwith terminates. 
The Microscope and its Revelations. By Wi.u1am B. 
Carpenter, M.D. Third Edition. London: Churchill. 
Tis work, which has now reached its third edition, needs 
no commendation from us. It is undoubtedly the best ma- 
nual on the use of the microscope in the English language. 
Nevertheless, this edition contains a large mass of new matter 
which claims our recognition. The classification of the Dia- 
tomaceze has been remodelled in accordance with the views of 
Mr. Ralfs, and the account of that group has been consider- 
ably extended. The account of the Rhizopoda has been alto- 
gether rewritten, and that of the Infusoria has been aug- 
mented by a summary of Balbiani’s recent researches on their 
sexual reproduction. As might be expected from the extent 
of the author’s own researches on Foraminifera, the chapter 
on these organisms has been rewritten and greatly extended. 
Mr. Salter’s researches on the teeth of Echinus, and those of 
Mr. Houghton on the parasitic habits of the larva of Anodon, 
have been embodied with the author’s more recent views of the 
structure of the shell in the chapter devoted to the Mollusca. 
Additions have been made also to the account of the forms of 
Annelida, and the description of the structure of the shells 
of the Crustacea have been considerably modified. In the 
section devoted to Insects, Dr. Hicks’ researches upon their 
eyes, and Mr. Beck’s upon the Podura scale have been de- 
scribed. Amongst the new accounts of structure among the 
vertebrate animals, are those of Mr. Whitney on the circula- 
tion in the Tadpole. Mr. Rainey’s important researches in 
“€ Molecular Coalescence” are also noticed in this edition. The 
work is still further improved by the addition of ten separate 
plates, and twenty woodcuts. ‘Two of the plates, represent- 
ing chiefly the circular forms of Diatomacez, are on steel, 
and form frontispieces to the work. It gives us much pleasure 
to recognise, in so large a quantity of the new matter which 
Dr. Carpenter has introduced into the present edition of his 
work, the results of researches which the ‘ Quarterly Journal 
of Microscopical Science’ has been the means of introducing 
to public notice. We feel that the study of this work will be 
one of the best incentives to the student of the microscope to 
pursue his inyestigations in a spirit which will enable him to 
become a contributor to our pages, and a future helper of 
Dr. Carpenter in the subsequent editions of his work. 
* Thuret, ‘ Ann. d, Se. Nat.,’ iv Sér., 1854, p. 2738. 
