228 BOTANICAL GAZETTE [MARCH 
normal showed that presence of the petiole between any two leaflets serves to 
widen the normal interval by about 37°. The leaflets of the leaves operated 
on were in each instance shorter than those of the normal leaves.—G. H 
SHULL, 
REINKE DISCUSSES the available sources of nitrogen for algae, espe- 
cially marine forms, and concludes that those which he and others have 
named heretofore, particularly the additions from the offal of cities, are 
entirely inadequate.3 In Kiel harbor, nitrogen bacteria (z. ¢., species capable 
of fixing free N dissolved from the air) have been found, notably CV/ostrid- 
tum Pasteurianum and Azotobacter Chroococcum, both in the mud at the 
bottom and in the mucilage covering the fronds of Laminaria, etc. Indeed, 
the latter are like agar plate-cultures of such species, Reinke suggests, 
therefore, that this is a sort of symbiosis, inevitably recalling the association 
of Rhizobia with Leguminosae, in which the bacteria get carbohydrates from 
the algae and give them nitrogenous compounds produced by the fixation of 
free N.—C, R. B. 
J. ERtksson*™ has pointed out that Professor Marshall Ward’s attack 
upon his mycoplasm hypothesis does not distinguish between the two essen- 
tial points involved, The first is the existence of an internal germ of disease ; 
the second the form in which such an internal germ may be conceived of as 
existing. The former point Eriksson would regard as proved, the latter as 
purely hypothetical; and hence he sees ‘no reason why rejection of the latter 
should involve repudiation of the former. He calls attention to the fact that 
Professor Ward’s work was carried on with artificial infections, when the 
whole theory rests upon outbreaks of the disease which cannot be explained 
by external infection; the theory having to do with that may be called the 
first stage of the disease, and Professor Ward's experiments with the second 
stage.—J. M. C. 
N. BERNARD has discovered some interesting peculiarities about the ger- 
mination of orchids.*S Seeds of Cattleya and Laelia germinate readily in about 
fifteen days, soon developing into minute green spherules. The plants rest 
here for some time and later slowly develop into a top-shaped body, which is 
always infested at the suspensor end by an endophytic fungus. In aseptic 
cultures the seedling does not go beyond the spherule stage, whence Bernard 
concludes that fungi are necessary even in the early stages of the orchid plant. 
By introducing the proper fungi, the ordinary slow growth may be much 
accelerated, and the resting period after the spherule stage may be much 
*3 REINKE, J., Zur Ernahrung der Meeres-Organismen disponiblen Quellen an 
Stickstoff. Ber. Deutsch. Bot. Gesells. a1 :371-380. 1903. 
“ ERIKSSON, J., The researches of Professor H. Marshall Ward on the brown 
rust on the bromes and the mycoplasm hypothesis. Arkiv for Botanik 1: 139-146. 
1903. 
*S BERNARD, N., La germination des Orchidées. Compt. Rend. 137: 483-485. 1903. 
