1907] CURRENT LITERATURE 145 
stamensis, and Encephalartos Barteri. We lays special stress on the strands of 
the foliar organs, his unit of primary importance in relation to phylogeny being 
what he calls the meriphyte, the vascular axis of the stem being of secondary 
portan Among other conclusions in reference to the strands of the leaves, 
c states (1) that the course of the vascular strands sometimes presents great 
complexities, and (2) that the classic @ of the foliar arc, although usual, is not 
general, referring particularly to Bowenia. A later paper'® deals with the struc- 
ture of the meriphyte of Bowenia spectabilis, and attempts to prove that the com 
plex arrangement of the foliar strands even in this form can be reduced to the 
typical 2.—R. THIESSEN. 
In anearlier paper M ‘9° noted in certai lat hylls of Ceratozamia 
the occurrence of three or more vascular strands near the abaxial surface of the 
sporophyll, in addition to the row of strands that usually appears in transverse 
section. These accessory strands showed reversed orientation, the xylem being 
on the abaxial side; and Marre regards this as an evidence of the union of two 
sporophylls along their edges.—Cuartes J. CHAMBERI.AIN. 
Problems of nutrition.—ArrTari published in 1904 an account of the influence 
of the different concentrations of glucose and saccharose upon the development 
of Stichococcus bacillaris and certain lichen-algae. This he now supplements?° 
by investigating the effect of different concentrations of each component of the 
nutritive solutions upon the amount and energy of multiplication in Stichococcus 
Chlorella (a new physiological species) and the algae from Xanthoria parietina. 
The concentration of NH,NO;, which was the source of N, has no effect on 
Chlorella below o.5 per cent., and on Stichococcus below 1 per cent.; but higher 
concentrations retard development, and suggest that the salt acts also in another 
way than by its osmotic pressure. The nutritive value of various sources of N 
varies according as glucose is present or absent. Glucose itself exercises an 
observable effect even at 0.005 per cent., and acts best between 0.5 and 2 per 
cent. The limiting concentration of monosaccharides, varying more or less with 
different algae, seems to be related to molecular, weight, since it is about equal 
in monosaccharides (glucose, galactose, and fructose), and approximately double 
this limit in disaccharides (saccharose and lactose), which also agree together. 
Many other details, not easily related, are also recorded. A few observations 
upon the effect of concentration upon the form and size of cells are given inci- 
dentally; the author seems not to know of LivincsTon’s papers on this subject. 
R.B 
"38 Marre, H. ser sew & la structure mériphytaire du Bowenia spectabilis, 
Compt. Rend. rey Sci. Paris, 409-416. 1905. 
19 Matte, H., Une anomalie de structure dans l’écaille ovuliftre de Ceratozamia 
mexicana. Bull. Soc. Linn. Normandie V. '7:52-54. 1903. 
20 ArTaRI, A., Der Einfluss der Konzentrationen der Nahrlésungen auf die 
Entwicklung einiger griiner Algen. II. Jahrb. Wiss. Bot. 43:177-214. 1906. 
