I884.J 
75i 
Analyses oj Books. 
author states, “ is confessedly an artificial arrangement which 
demands apology, but can scarcely receive justification. The 
only excuse which can be offered is that it serves the purpose of 
those for whom the present work was written, namely, the micro- 
scopists who desire some acquaintance with the organisms met 
with in their excursions to ponds and ditches. This class of 
students certainly deserve such assistance : their limited time for 
study is mostly spent at the microscope, or out of doors collecting 
specimens, rather than in searching through libraries and over- 
whelming masses of periodical literature. They work earnestly 
and yet leisurely, and nothaving to cramfor passing examinations, 
dispense with the services of the professional coach ; if the aid of 
someone knowing more than themselves is needed, it is found at 
one of the natural history societies which now abound all over 
the kingdom, and the strange specimen sooner or later reaches 
the hands of an expert, who is able to tell something about it, or 
still more humbly to say he does not know, and advise how 
further research is to be conducted. Those who have had the 
good fortune to meet the author of the present work either at the 
Quekett Club or at one of his excursions, will know how to value 
the instructions and hints of so genial a teacher — one who loves 
science for its own sake. 
The introduction contains a concise history of the subjeCt, from 
which it appears that in Ray’s time about twenty species of Fresh 
Water Algae were known ; these had increased to eighty-eight at 
the publication of Dillwyn’s “ British Confervse ” in 1809. 
The next important work was Hassall’s “ Fresh Water Algas,” 
published in 1845, containing descriptions and figures of two 
hundred and ninety-seven species. Since that time the student 
in search of information respecting these organisms must have 
sought for it through the over-increasing mass of scientific peri- 
odical literature. The present work contains descriptions of four 
hundred and thirty-eight species. Respecting the omission of 
the Desmidieae, the author must answer for himself. “ This 
large and interesting family is designedly excluded, as it is pro- 
posed to treat them separately. As so many students confine 
themselves exclusively to this family, this proposal will doubtless 
commend itself. The excellent text-book by J. Ralfs has long 
been the standard for English students, and would be so still but 
for its scarcity and the large number of additions in the interval 
since its publication.” Similar remarks will apply to the more 
numerous family of Diatomaceas. The coloured plates are 
beautifully executed, and in many instances are from the author’s 
own drawings, in which case the magnifying power invariably 
accompanies the figure. 
A list of the authorities quoted, and what is even more useful 
to the readers for whom the book is intended, a well-compiled 
glossary, form part of the work. 
While congratulating the author on the completion of his book^ 
