960 THE AMERICAN NATURALIST. [VoL. XXXII, 
case, very few of the species have been seen by their authors except 
as dried specimens ; any one who has given any attention to the 
genus must recognize the difficulty of distinguishing many of the 
described species. With the intention of doing what was possible 
towards clearing up the subject, Mme. Weber-Van Bosse has made 
it a special study for several years, and the result is the paper just 
published in the Annales du Jardin Botanigue de Buitenzorg. 
Two long voyages to the tropics, specially for the observation of 
the living plants, and a careful study of the specimens in all the 
great herbaria of Europe, including authentic specimens of practi- 
cally all described species, have placed the author in a position to 
carry out the work in a way heretofore impossible ; and the paper 
which is the result of her studies leaves apparently little to be done 
in the way of classification and general arrangement of the genus. 
The grouping is practically the same as in Agardh’s memoir of 1872 ; 
but the specific limits change considerably ; varieties and forms in 
several cases representing what were before considered good species. 
Agardh’s paper gave sixty-four species; De Toni’s Syl/oge, 1889, 
seventy-four, not including doubtful species ; Mme. Weber describes 
five new species, but, including these, her list is only fifty-four. Any 
one who has struggled to distinguish the Florida and West Indian 
C. juniperoides, C. cupressoides, C. ericifolia, etc.,.not from a single 
specimen of each, but from a lot of some hundreds, will appreciate 
the justice of a classification which unites under C. cupresoides these 
and four more of the older species. 
In the matter of nomenclature a number of changes have been 
made, usually to substitute an older specific name for the one com- 
monly received ; though in one or two cases, where this would result 
in the substitution of an obscure and also inappropriate name for a 
universally known and appropriate one, the change has not been 
made. The introductory chapter contains a full account of previous 
studies on the structure and growth of Caulerpa; the plates are 
excellent; the descriptions full ; and the synonymy very complete, so 
much so that the absence of any index is a matter for regret. 
As to the question of fructification, there are only a few tantalizing 
hints: in two instances, each in a different species, an arrangement 
of the protoplasm similar to that which precedes the formation of 
spores in certain genera of green alge ; the fact of the disappearance 
of certain species during certain months, and their regular reappear- 
ance; and one or two other indications pointing to the probability of 
growth from spores ; these are all that we can learn. But the author 
