a 
210 BOTANICAL GAZETTE [MARCH 
The appearance of Nordstedt’s Index is welcomed by all students of 
desmids as an exceedingly useful work. During his thirty years of work on 
the desmids the author has labored to keep up with the bibliography, and 
while the present index is not quite complete, bibliographers know how diffi- 
cult a thing it is to have access to every article published upon a subject so 
much written about. The index is, however, approximately complete, and 
one can gain a good notion of its fullness from the fact that about 1200 titles 
are listed. Over twenty exsiccate are listed which contain desmids among 
in some cases the desmid numbers being given. The index 
proper Sectaion families, genera, species, subspecies, varieties, and forms, 
arranged alphabetically, and the citations under each are arranged in chrono- 
logical order, giving abbreviated names of authors and titles of the 
work in which the species is mentioned, so that the entire literature of 
each species is indicated. Under each citation is indicated what the char- 
acter of the reference to the species is, as description, observations or 
notes, measurements only, name only, description of zygospore, figure 0 
zygospore, other illustrations cited by number and plate. In the index there 
are about 24,000 such citations (under Botrytis alone about 180). All names 
are included in the index which would be needed in a study of the synonymy. 
Following the usual addenda is a chronological list of genera, and an alpha- 
betical list of species under the genera.—G. 
The African flora. 
THE flora of Africa has received lately a largely increased share of atten- 
es and our = seas essa is being flooded with descriptions of 
f various groups. One of the most prom- 
inent names connected ie a African flora is that of Dr. Welwitsch, who 
was commissioned by the Portuguese government to explore their African 
possessions, broadly known as the province of Angola. In 1853 this explorer 
began his work, and in the face of tremendous obstacles in the way of sickness, 
difficulty of travel, opposition of natives, etc., spent seven years in the most 
unremitting labor. His herbarium is undoubtedly the best and most extensive 
ever collected in tropical Africa. The riches ot his collections were indi- 
cated 
from ees ae ite benoit his own en and those of the vari- 
yhom he submitted material. Permission was obtained 
from. the joa government to a3 his collections “to England and — 
: other northern countries” for study, and to this study he devoted the rest 8 
~ life, his death occurring in 1872. His name is familiar to every botan 
as the — of Welwitschia, so elaborately described by Sir jane 
Berlingianis, 1896. ( acces M. 20. 
isiasM as a collector may be inferred from his sensations 
Regie 5 Societatis scient._ _Holmiens. collatis eet ~ Ppp- 310. Lunde, trpis a 
