370 The American Naturalist. [April, 
favorable conditions variations may arise, e. g., great elongation of 
the promycelium when grown in an excess of water, or its great short- 
ening when the moisture was insufficient. In the latter case the short 
promycelial cells readily fall apart, and under favorable conditions 
grow into hyphe. Spores of the latter kind Kienitz-~Gerloff considered 
to be uredospores, but Mr. Richards shows conclusively that their 
peculiar germination is due to special conditions, and that they are 
therefore to be still regarded as teleutospores. 
Hackel’s Revision of the Andropogonez.—The sixth vol- 
ume of the ‘‘ Monographie Phanerogamarum’”’ of the De Candolles is 
a notable work of over seven hundred pages, entirely devoted to a 
monograph of a single tribe of the great order of the Graminez. 
When one observes that in this book there are descriptions of 420 
species, the vastness of the undertaking of the noted author is made 
evident. At the present rate it will require from five to seven thou- 
sand pages in all, or from six to eight or nine additional volumes like 
the present one. 
Hackel divides the tribe Andropogonee into five sub-tribes, to 
which he assigns the thirty genera which he recognizes. The scheme 
of classification may be made out from the following synopsis : 
ANDROPOGONE®. Kth. ampl. 
Sub-tribe I. Dimerieze Hack. 
Genus 1. Dimeria R. Br. Japan, Malay Archipelago, Austra- 
Ha <1 Spi 
Sub-tribe II. Saccharez Benth. & Hook. 
Genus 2. /mperata Cyril. Tropical and Sub-tropical. 5 sp. 
‘¢ 3, Miscanthus Anderss. Asia. 7 sp. 
‘¢ 4. Saccharum Linn. Tropical and Sub-tropical. 12 sp. 
“© 5. Erianthus Michx. ‘Tropical and Temperate. 18 sp. 
‘¢ 6. Pollinta Trin. Tropical Eastern Hemisphere. 29 sp. 
‘< 4. Spodiopogon Trin. Eastern Hemisphere. 5 sp. 
“oo 3. Polytrias Hack. Java. 1 sp. l 
“ 9. Pogonatherum Beauv. Eastern Hemisphere. 2 sp. 
Sub-tribe III. Ischæmeæ Hack. 
SFO 10. Apluda Linn. Tropical Eastern Hemisphere. 1 sp. 
11. Jschæemum Linn. Tropical Eastern Hemisphere. 42 sp. 
“ 12. Lophopogon Hack. India and Australia. 2 sp. 
‘« 13. Apocopis Nees. Asia. 2sp 
‘¢ 14. Eremochioa Büse. Tropical Asia. 8 sp. 
“ 15. Thelepogon Roth. India and Africa. 1 sp. 
