20 EXTRACTS AND ABSTRACTS, 
cetes, the sexual reproduction of which both Brefeld and Van Tieg- 
hem so strenuously aeny, the former observer finding a distinct proof 
of his theory in the circumstance that the Hyphe on being cultivated 
in a nutritious ator produced ee Dieta filaments with- 
out forming Asc 
AsB Brefeld’s views on the alternation of generations of the Asco- 
mycetes take the relations existing in Vascular Cryptogams as a point 
of departure, it was first ofall the question whether the production of 
the sexual generation was necessarily bound up with the formation of 
e ee were instituted thus. The pompeonia. were 
partly extracted from their mother-plants—a | process which can usually 
be effected without injury—and partly cut off directly above the point 
of their connection ; all were placed on damp earth under a bell-jar, 
- seapreet to diffused deplieht Not a few soon showed clear 
of decay; others again remained green and unaltered in shape, 
oan the acai of some deformations of the capsule. After two or 
three, months, however, dense protonema-formations, on which leaf- 
bearing Moss-plants were already formed, proceeding from the cut 
showed the way they arise. After a 
lapse h the three months the suntents of most of the seta-cells had died in 
; tiss ich not only retained 
their pro prtspas aad ehloroplgi Tot Shad eed the volume of the 
de vii 5 tis, pose see isolated and sometimes in groups, the 
individual cells arranged beside or above each other. n: from cells 
in nA wall of the capsule Dr. Stahl found protonema fait to 
uced sexually, r 
of Dr. Stahl eis performed last narra in the . — 
G 2M. 
The ents 
Strasburg Bi Botanical Laboratory. 
it oe eS eet 
