Entwicklungsgeschichte 
27 
contain about four nuclei. In a few of the cells of each ascogonium 
there is usually to be found a nucleus with a huge nucleolus. The origin 
of these special nuclei could not be traced. “No convincing evidence of 
fusion of ascogonial nuclei could be obtained, though the common close 
association of the nuclei in pairs and the difference in the size of the 
nuclei of a single cell suggest that such fusions may still take place in 
spite of the abortive nature of the ascogonia.“ Though not in structural 
connection with the ascogonium the perithecium arises in its neighbour¬ 
hood. The cells of the ascogonia do not become emptied of their contents. 
The perithecia are first distinguished as groups of special hyphae which 
arise from small-celled hyphae surrounding the ascogonium. The cells of 
these special hyphae may have the nuclei arranged in pairs. The asco- 
genous hyphae become differentiated towards the base of the young peri¬ 
thecium: they arise by differentiation from the perithecial hyphae which 
are of vegetative origin. At the time when the ascogenous hyphae are 
differentiating there may be seen besides the nuclei in pairs larger nuclei. 
“Nuclei in close contact are also seen and in one case what appeared to 
be a stage of nuclear fusion. . . . There are thus indications that at this 
stage a nuclear fusion occurs which replaces a normal sexual fusion now 
lost.“ The details of the formation of the asci and the ascospores was 
not followed, since the fungus is not a suitable one for the study of such 
phenomena but there were indications that the ascus is formed in the 
normal way with fusion of nuclei in the penultimate cell of an ascogenous 
hypha. J. Ramsbottom (London). 
BARRETT, j. T., The development of Blastocladia strangulata 
n. sp. (Bot. Gaz. 1912, 54 , 353—371; 3 pi.). 
The author’s summary is as follows. The plant resembles in general 
the other species of the genus. Its mycelium is definitely constricted, 
which fact, it seems, definitely places the genus in the family Leptomi- 
taceae. 
It possesses peculiar perforated pseudo-septa which are formed at 
the constrictions, and which in a way are comparable to the “cellulin 
rings“ of other members of the Leptomitaceae. 
Zoosporangia are provided with a number of papillae of dehis¬ 
cence distributed over the surface, which are formed as the result of the 
gelatinization of small circular areas of the wall. The resulting plug is 
made up of two distinct parts, the inner of which forms a vesicle into 
which the zoospores escape at the time of their discharge. 
The zoospores possess a large centrally located subtriangular mass 
of apparently some reserve food substance, probably proteid in nature, 
at whose base is located the nucleus. They are typically uniciliated, with 
the cilium in direct relation to the nucleus. 
Resting sporangia possess a three-layered wall; the outer and 
inner layers thin and hyaline, and the middle thick, perforated, and 
orange coloured. After a period of rest of several weeks, germination 
takes place by the formation of zoospores. 
On germination the zoospore produces a germ tube which forms 
the basis of the rhizoid system, while the body of the spore becomes the 
basal cell of the plant. Nuclear division is somewhat unusual, apparently, 
and reminds one of amitosis. It seems to the writer however, that it 
