1916] CURRENT LITERATURE 241 
Artificial parthenogenesis and fertilization 
This belated’notice of LorB’s book? was suggested by the fact that it does 
not seem to have aes known in botanical circles to an extent worthy of its 
significance. The erial is almost wholly zoological, but the book deals 
with such A Rasa? problems that it cannot fail to be of interest to all 
biologists. Chap. iv, on “Hydrolytic processes in the germination of oil- 
containing seeds,”’ and chap. xxix, on “Artificial parthenogenesis in plants,” 
are of special botanical interest. It must not be inferred from the title that 
Loes attempts a systematic presentation of the phenomena in animals and 
plants; on the contrary, he presents for the most part his own results, his own 
methods of work, and his own points of view; and as these have concerned so 
preponderatingly the subject of artificial parthenogenesis, fertilization comes 
book, and has gone beyond the standpoint of the book in other particulars. 
The book is of interest in two particular respects: (1) as a presentation 
of the author’s own classical work in this field which he has done so much to 
illumimate, and (2) as a splendid example of biological analysis which takes a 
particular genetic process out of the realm of morphology and attempts a 
thorough Rae analysis, relating it as far as possible to physico-chemical 
processes on the one hand and to seemingly remote biological processes 
the other hand. The ities is so fresh and original in his point a view that 
one cannot fail to profit by the presentation as a study in scientific method. 
There are few biologic books in which this connection naan hypothesis and 
discovery is more convincingly illustrated —F. R. Liv 
Phoradendron 
Probably no genus of plants has been given more elaborate and detailed 
treatment than the exclusively American genus Phoradendron has received in 
the recent monograph by TRELEASE. It is the record of a prolonged and 
painstaking study of a difficult and poorly known group. In this monograph 
277 spgcies are recognized, and et Beem eeenron | is very interest- 
ing. The two primary groups a med “‘Boreales” and “ Aequatoriales,” 
and the names indicate their esslnitiaa, Of the 66 species vf the former, 28 
occur in the United States, 48 in Mexico, 2 in Central America, and none in 
the West Indies and South America; while of the 211 species of the latter, 
hone occur in the United States, 29 in Mexico, 20 in Central America, 38 in 
the West Indies, and 134 in South America. The new species are remarkably 
2 Logs, J., Artificial ae and fertilization. The University of Chicago 
Press. 8vo. pp. x+312. figs gI3. 
3 TRELEASE, WILLIAM, oe genus Phoradendron. Large 8vo. pp. 224. pls. 245. 
Urbana: University of Illinois. 1916. 
