172 MORPHOLOGY AND TAXONOMY OF ALGAE [Bot. Absts., Vol. VI, 



the hypobasal cell of the four-celled stage. The Chenopodiaceae agree with the Polygonaceae, 

 however, in that the basal cell of the two-celled stage contributes to the hypocotyl, and in 

 that the cortex initials arise in the tissue produced from the hypobasal cell of the tetrad stage. 

 — C. H. and W. K. Fan: 



1186. Ulehla, Vladimir. Studien zur Losung des Windesproblems. [Wind problems.] 

 Bot. Notiser [Lund] 1920: 1-30. 1920. 



1187. Wells, B. W. (Note without title.) Plant World 22: 251-252. 2 fig. 1919.— An 

 abnormal inflorescence of Allium mutabile is described. Certain stamen primordia had de- 

 veloped flowers instead of stamens. It is suggested that the peculiar development may give 

 a clue to the development of the compound umbel as a type of inflorescence. — Charles A. Shull. 



1188. Wells, B. W. Early stages in the development of certain Pachypsylla galls on Celtis. 

 Amer. Jour. Bot. 7: 275-285. 1 pi. 1920. — The galls produced on leaves of species of Celtis 

 by Pachypsylla mamma and P. asteriscus were studied. The life history of the insects is 

 briefly outlined and the histological phenomena accompanying gall formation described. The 

 newly hatched nymph inserts its proboscis into the upper side of the leaf and remains in this 

 position during gall formation. A thin sheath is laid down around the seta by the cytoplasm 

 of the cells which it penetrates. Through hypertrophy of the epidermis and mesophyll cells 

 on the opposite (lower) side of the leaf, a downward evagination is produced which lowers 

 the insect into the body of the leaf. A "cover-cone" now springs up on the upper surface 

 from tissue adjacent to the larva and rapidly grows over the insect, enclosing it in the gall. 

 Chloroplasts degenerate and nuclei increase in size in the zone below the larva. Multinucleate 

 cells appear in the tissues of the floor of the larval chamber, and the author believes their 

 nuclei to arise amitotically. The grand period of growth for the gall is early in its existence, 

 while that for the larva itself does not come until the gall is more than half grown. No clue 

 was obtained as to the nature of the stimulus which causes the development of these very spe- 

 cific gall structures. — E. W. Sinnott. 



MORPHOLOGY AND TAXONOMY OF ALGAE 



E. N. Transeatj, Editor 



1189. Anderson, Emma N., and Edna R. Walker. An ecological study of the algae of 

 some sandhill lakes. Trans. Amer. Microsc. Soc. 38: 51-84. PI. 3-12, 17 fig. 1920. 



1190. Butterfield, W. M. A vegetable manufacturer of decorated glass. Sci. Amer. 

 122: 116, 122-124. 1 fig. 1920.— Description of diatoms in popular style.— Chas. H. Otis. 



1191. Carter, Nellie. Studies on the chloroplastids of Desmids III. X. The chloro- 

 plasts of Cosmarium. Ann. Botany 34: 265-286. PI. 10-13, 88 fig. 1920.— Most of the spe- 

 cies of Cosmarium examined have axile chloroplasts in each semicell; in a few the chloroplasts 

 are parietal. The number of pyrenoids depends upon the individual, and at any time a group 

 of pyrenoids may be formed where originally there was only one. — E. N. Transeau. 



1192. Chodat, R. Sur un Glaucocystis et sa position systematique. [Concerning Glauco- 

 cystis and its systematic position.] Bull. Soc. Bot. Geneve 11: 42-49. 2 fig. 1919. — From 

 a careful study of the life history of a species of Glaucocystis the genus is placed in a new fam- 

 ily of Dinoflagellateae. The new family Glaucocystaceae has the following characteristics: 

 the cellulose membrane has internal polar thickenings; a large nucleus with a nucleolus, chro- 

 matophores strap-shaped and peripheral in distribution or arranged in two radiating groups 

 with a clear space on one side of the cell between the two groups of chromatophores which 

 makes the cells asymmetrical. Multiplication takes place as in Oocystis. The plants are 

 abundant on mosses and Equisetum growing in small streams. — W. H. Emig. 



