398 BOTANICAL GAZETTE | MAY 
SCHAFFNER,* in continuing his studies among the lower monocotyledons, 
concludes that the placing of the Nymphaeaceae near the Helobiae is justi- 
fied. He holds that the embryonal and anatomical characters, as well as the 
more superficial features of the group, would suggest the Helobiae as near 
_ relatives. He opposes the supposition that all so-called cotyledons are 
homologous, and suggests that instead of having only two general types in 
angiosperms there are several types which approach each other at various 
points in widely separated orders.— R. B. WYLIE. 
BACHMANN ® has attempted to summarize our knowledge of phytoplank- 
ton, covering the whole subject, from definitions of plankton and descriptions 
of methods of collection to the distribution of the phytoplankton and its rela- 
tion to other organisms. This is followed by a bibliography of about ten 
pages, and hence it cannot be very complete. The paper adds nothing to 
what has already been published, but gives a very good résumé of what has 
been done, and perhaps as good a statement of the present state of knowl- 
edge as could be expected in a brief article.—C. D. MARSH. 
SEVERAL INTERESTING OBSERVATIONS regarding plasmolytic phenomena 
in the blue-green algae are made by Brand.” Among the most striking are 
these. Thalli of Phormidium, etc., when strongly plasmolyzed by a salt 
solution and then placed in pure glycerin, are able to absorb this substance 
much as they might water, and thus return to their normal form. They live 
thus, filled with glycerin, for a number of hours. Furthermore, if cells so 
filled with glycerin are placed in water they stretch to beyond their normal 
size and often burst from the high internal pressure,— B. E, LIVINGSTON. 
FROM His STUDIES of the foliar bundles of young plants of Cycas revo- 
luta and Zamia integrifolia, Enrico” concludes that, though most of the cen- 
trifugal xylem is of secondary origin, a small portion is primary and is derived 
from the centripetal wood. ‘This implies a near relationship to the distinctly 
mesarch structure of the vascular strands of ferns. The author considers that 
the changes seen in a foliar bundle in its ontogeny and in its course from the 
leaf tip to cortex of the stem represent the phylogenetic development of the 
bundle of the higher plants. The phloem shows two maxima of development 
in its young stages; this is interpreted as an ancestral character.—M. A. 
CHRYSLER. 
24 SCHAFFNER, J. H., Some morphological peculiarities of the Nymphaeaceae and 
Helobiae. Ohio Naturalist 4: 83-92. pls. 5-7 
25 BACHMANN, H., Das Phytoplankton des Siisswassers. Bot. Zeit. 627: 81-100. 
1904. 
26BRAND, F., Ueber das. osmotische Verhalten der Cyanophyceenzelle. Ber. 
Deutsch. Bot. Gesell, 2z: 302-309. 1903. 
27Enrico, C., V. Contribuzione alla conoscenza della morphologia ¢€ dello 
sviluppo del fascio vascolare delle foglie delle Cicadacee. Annales di Bot. 1: 109- 
121. pls, 8-9. 1903 
