168 BOTANICAL GAZETTE [SEPTEMBER 
priority in origin, takes the ascendancy and appropriates the proto- 
plasm for the development of the sporiferous head. 
That the umbilical stalk is formed directly from the stem arising 
from an anastomosis and is at least the chief channel through which 
the fructification receives its supply of nourishment is indicated bya 
number of facts. Its base is at first in connection with the fine 
anastomosing hyphae, but as the plant reaches its full size it shrivels 
and usually leaves at maturity little more of a remnant than shown 
in fig. 9. In cases in which its base remains, it may be seen to be 
somewhat raised above the attachment of the two pairs of legs, as if 
it had been torn out of the substratum by the growth of these latter. 
The legs are obviously a later production, as is seen by fig. 8, where 
the anchoring rhizoids are just beginning to be given off toward their 
bases. The legs, as may be seen in the left hind leg of the specimen 
just mentioned, are supplied with rhizoids which at times certainly 
- are comparatively short and end blindly; although in other cases @ 
few of the rhizoidal branches.can be followed for a certain distance 
into delicate filaments characteristic of the mycelium. This latter 
condition, however, is not so typical as for the umbilical stalk. 
Neither the vegetative mycelium nor the hyphae of the fructifi- 
cation are septate during growth. Septation regularly takes place 
in the neck, legs, and branches of the head when the protoplasm 
which they contain becomes used up in spore-formation, and mature 
spores showing the characteristic echinulations are to be found on 
fructifications in which no septa have as yet been found. The cto 
walls are thin in comparison with the thick lateral walls and aut 
irregularly disposed. Often one connects the lateral wall with 
adjacent septum or extends as a shelf but part way across the hypha. 
The branches of the crown easily separate at their septa, an@ 07 — 
judicious tapping with a needle the crown may be denuded of neary 
all its sporiferous heads and branches. = ce 
The only known form to which Thamnocephalis shows any close 
relationship is Sigmoidiomyces dispiroides Thaxter,* and the two 
genera evidently form a group by themselves. ‘The method of spore 
4 THAxtTER, R., North American Hyphomycetes. Bor. GAZETTE 16:22. 
figs. 15-18. 1891. Figures reproduced in ENGLER and PRANTL’s Pflanzeni®™ 
11:427. figs. 220 G-H. es 
