1887. ] BOTANICAL GAZETTE. 255 
CURRENT LITERATURE. 
Pittonia, Vol. i, part 2. A series of botanical papers by Edward L. Greene, 
July, 1887, pp. 51-93. 
When the first part of Pittonia appeared the question as to the mean- 
ing of the name was raised. This has called forth an explanation in the 
part before us, which explains that an easy name was sought, to be used 
in quoting, and so the family name of Tournefort was chosen. Two new 
described. The part closes with an account of an excursion to the island 
of San Miguel, and a catalogue of its flowering plants. 
Untersuchungen iiber Bau wnd Lebensgeschichte der Hirschtriiffel, Elaphomy- 
ces, von Dr. Max Rees und Dr. C. Fisch. Bibliotheca Botanica, Heft 
7, quarto, pp. 24, pl. 1. Cassel, Theodor Fischer, 1887. 
The obscure life history of truffles has received additional treatment 
by the authors, who corroborate the constant limitation of species of 
ces to soil permeated by the roots of trees—eccording to their 
observation, pines—that are closely invested and parasitically attached by 
;  Srowing mycelium, which matures its fruit only when in the most 
Mtimate connection with the abnormally branched rootlets. The con- 
nection between mycelium and roots appears to be simply that of a para- 
Site with its host, and not a case of true symbiosis. Although plants were 
¢xamined in large numbers, and in all stages of development, no trace of 
fertilization was observed, so that the fruit appears to be strictly non- 
Sexual, as in the pileate fungi; but this retrogression has progressed 
further than in the latter, for many of the fruits fail to mature, and, 
though produced in myriads, the spores seem to have entirely lost the 
Power of germination, and propagation is only known to be effected by 
the spreading of mycelial fibers from root to root. ——~*V . 7: 
Lectures on the Ph: siology of Plants. By J lis, von Sachs j Part te 
a. 3 . 8, OD. ZY, >. 
455. Clarendon Press, Orion: 1887, (New York: Macmillan & Co.) 
- English speaking students of plant physiology. Sachs’ admirable 
" Vorlesungen iiber Pflanzen-physiologie,” issued in 1882, has been turned 
into excellent English by Prof. Ward, and thus added to the list of books 
*ssential to the working library of our laboratories. However much it 
's to be regretted, it is a fact that our American students can not make 
ready use of German books, and a translation is always welcome; partucu- 
larly such a book as this, in which, in lecture form, the author sets forth 
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