334 BOTANICAL GAZETTE [OCTOBER 
papers deals with the morphological nature of the so-called stem, which he 
calls ‘‘stock,’”’ the reason being that one of the questions is whether this tuber- 
ous axis represents only a short stem. After a presentation of the anatomical 
details, LANG concludes that the stock consists of an upwardly growing shoot 
region, and a downwardly growing region giving rise to the roots; the latter 
region he calls the rhizophore. He suggests that the origin of the rhizophore 
may hold some relation to the deep-seated secondary meristem at the base of 
the shoot, but that, once initiated, “the growing region of the rhizophore 
behaves like the primary axis which is congenitally sunken and inclosed.” 
This region, it seems, is very suggestive of the basal root-bearing region of 
epidodendron and He allies, and confirms WILLIAMSON’s suggestion that 
Isoetes may be the nearest living representative of that paleozoic stock.— 
M.C 
Phylogeny of the Ascomycetes.—ATKINSON,*4 in a paper presented at the 
twenty-fifth anniversary celebration of the Missouri Botanical Garden, dis- 
cusses at length the vexed question of the origin of the Ascomycetes and their 
interrelationships. In general his thesis is that the Ascomycetes have been 
derived from the Phycomycetes, rather than from the red algae, the possible 
transitions being suggested most strikingly by such a form as Dipodascus. 
The details of the argument are too numerous to cite here, but it is well sus- 
tained, and more convincing than any argument hitherto favoring the algal 
origin of the group. A chart presents in graphic form the conclusions as to 
interrelationships, the Protoascomycetes arising from the Phycomycetes, and 
in turn giving rise to the Euascomycetes through the Dipodascus “sto Pri sd 
The divergent lines of the Euascomycetes are represented as emerging from 
two primitive overlapping stocks (Gymnoascus and Monascus). The paper is 
a very important contribution to our knowledge of a perplexing group.— 
JMC 
Cecidology.—One of the latest American papers on cecidia is by FEtt,* 
in which the author describes a very large number of species of midges, many 
of which cause galls, while others are more or less closely associated with galls. 
Although this paper is primarily entomological, it contains many descriptions of 
galls which are of value to the botanist. 
% Lanc, WittiaM H., Studies in the morphology of Jsoetes. I. ,The general 
morphology of the stock of Isoetes lacustris. Mem. and Proc. Manchester Lit. and 
Phil. Soc. 59: no. 3. pp. 28. 1915. 
+4 ATKINSON, GEO. F., Phylogeny and ‘ieepaemtesal in the Ascomycetes. Annals 
Mo. Bot. Gard. 2: nee. Jigs. 10. 1915 
*s Fett, E. P., A study of gall midges II. Itonidinae. Rep. N.Y. State Entomol. 
1913. Pp. 79-211. 
