ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
345 
Protophyta. 
a, Schizophyceae. 
Structure of Schizophyceae.* — Herr S. Stockmayer reviews our 
present state of knowledge of the structure of Schizophyceae, ’which he 
regards as Algae with no true nucleus and no chroraatophore. He was 
able to detect, in some species, a distinct reticulate structure in the 
central body. The Glaucocystideae t appear to consist of genera of true 
Algae which contain phycocyan. 
Dictyosphaerium4 — Prof. A. Borzi points out that the observa- 
tions of Zopf § on the life-history of Dictyosphserium are very much in 
accord with those already recorded by himself. The chromatophore has 
not, as has been stated, the form of a disk, but of a solid substance, 
frequently that of a segment of a sphere. The author considers the 
nearest allies of Dictyospliserium to be Schizochlamys and Dictyocystis. 
To these observations Zopf replies. || 
Growth of Diatoms in Surface- Waters.^ — According to Mr. G. C. 
Whipple, the growth of diatoms in ponds is directly connected with the 
phenomenon of stagnation ; their development does not occur when the 
lower strata of water are quiescent, but rather during those periods of 
the year when the water is in circulation from top to bottom. They 
flourish best in ponds with muddy bottoms. In deep ponds there are 
two well-defined periods of growth, in the spring and autumn. The 
two most important conditions of growth for diatoms are a sufficient 
supply of nitrates and a free circulation of air. Temperature has but 
little influence on their development. 
Gloiotrichia echinulata.** — According to Herr P. Kichter, this alga, 
which is a frequent constituent of “ flos aquas,” has the property of 
extracting sulphur from the water, this being the cause of the red 
granules frequently observed in this organism. It has frequently been 
■confounded with Rivularia Pisum. 
Motility of the Cyanophyceae.jf — Herr S. Strodtmann attributes 
the power of spontaneous motion in Gloiotrichia echinulata to the 
red granules described by Richter. Under certain conditions these red 
granules are wanting, and the alga then sinks instead of floating. The 
red granules are probably vacuoles filled with a gas and enclosed in 
protoplasm, which serve to float the “ flos aquae ” on the water. 
Gas-vacuoles in the Cyanophycese.JJ— Dr. II. Klebahn has investi- 
gated the nature of the red bodies which occur especially in those Algae 
belonging to the Phycochromaceae which form “ flos aquae ” on the 
surface of fresh water. He assigns reasons for concluding that they 
* Ber. Deutscli. Bot.Gesell., xii. (1894) Gen.-Vers.-Heft, pp. 102-4. 
t Cf. this Journal, 1892, p. 830. 
X Ber. Deutscli. Bot. Gesell., xii. (1894) pp. 248-55. Cf. this Journal, 1891, 
p. 637. § Cf. this Journal, 1894, p. 605. || Tom. cit., pp. 344-5. 
f Technology (Boston), vii. (1894) pp. 214-31. 
** Forschungsber. Biol. Stat. Plon (Zacli arias), pp. 31 47. See Hedwigia, 
xxxiii. (1894) Rep., p. 35. ff Biol. Centralbl., xv. (1895) pp. 113-5. 
XX Flora, lxxx. (1895) pp. 241-82 (1 pi.). 
