50 
DESCRIPTION OF PLATE X. 
Figs. 1- 5. Puccinia heterospora, B. and C. The spore contents are not drawn with 
tho same magnifying power. 
6-21. Puccinia heterogenca, n. s. 
1- 3. One-celle'd spores. 
4- 5. Two-celled spores. 
6- 9. Two-celled spores, of which 7 and 9 have germinated. 
10-13. Oue-celled spores, of which 12 and 13 have germinated. 
14. A one-celled spore which has germinated, and the promycelium divided 
into five cells. 
15. A two-celled germinated spore; the promycelium has divided into four 
cells. 
16. Sporidia. 
17. A germinated spore whose promycelium has fallen apart into single 
cells. 
18. Isolated cells of the promycelium. 
19-21. Spores which have germinated in water and formed a long germ tube. 
In Fig. 21 the germ tube is branched at the end. 
REVIEWS OF RECENT LITERATURE. 
Brefeld, Oscar.— TJntersuchungen am deni Gesammtgebiete der Alyko- 
logie. Heft IX. Munster i. W. 1891, pp. VIII, 156, pi. 4. 
This indefatigable German botanist has recently given to the press 
the ninth part of the above work, and by this time no doubt has the 
tenth part before the public. These two parts represent 10 years of 
investigation, the last four of which have been entirely devoted to 
this work. Owing to the loss of one eye he has been obliged to have 
the constant help of an assistant, whose aid he acknowledges both in 
the prospectus and on the title page. The assistants in the work were 
Dr. Franz von Tavel and Dr. Gustav Lindau. 
Dr. Brefeld feels that with the issue of these two parts and the 
plans of three more in hand, he can at least fully claim that he has laid 
the foundation for a natural system in the classification of fungi—a 
system which hitherto has made itself painfully conspicuous by its ab¬ 
sence, and which can not be too warmly welcomed, or too thoroughly 
studied by American mycologists. 
Part ix consists of five divisions. The first division is explanatory 
of the rest. The second takes up spermatia and their culture in nutri¬ 
ent solutions, shows that they are capable of germination and inde-' 
pendent development and hence are a form of asexual reproduction 
distinguished from other spore forms only by their size. 
Division 3 deals with the asci of Ascomycetes in their relation to ba- 
sidia and simpler fruit forms. In this the author traces the relationship 
between conidia and sporangia and attempts to establish that the former 
is only a variation of the latter. Starting with these two he traces the 
