The Metaholism of Trees. 61 
Conjugatio vulgo inter cellulas singulas post dissociationem 
filamentarum, rarius inter cellulas duarum filamentarum sine 
dissociatione. 
Zygosporis rotur.do-quadratis, lateribus levissime retusis vel 
rarius rectis; angulis cornutis, cornubus cylindricis, solidis, apicibus 
ato-truncatis vel sub-truncatis. 
Long cell veg. ... 38-50/a. lat. ... 10-12 /a. 
„ ' zyg. 28-32/a. „ ... 20-24/a. 
„ corn. 8-40/a. . 10-1 2/a. 
Hence Figs. 1 and 2, N.P., Vol. X, PI. 2, are really figures of a 
Mougeotin, probably M. gvacillima. 
Professor West also informs me that the suggested comparison 
of the cruciate arrangement of the zygote with Peninm didymo- 
carpuiu does not hold good. 
Thus, as was stated before, the species is closely allied to D. 
desmidioides, West. The zygote characters are very similar, but 
the filaments are thicker and are not constricted as in that species. 
The following reference with in penultimate para-graph, p. 
89, was omitted :— West, W. “ Monograph of British Desmids,” 
1904, Vol. I, p. 22. 
S. R. PRICE. 
NOTES ON RECENT LITERATURE. 
PHYSIOLOGY. 
The Metabolism of Trees. 
Ramann & Bauer. “ Trockensubstanz, Stickstoff und Mineralstoffe von 
Baumarten wiihrend einer Vegetationsperiode.’ : Jahrb. f. wiss. Bot., L, 
1911, p. 67. 
Bauer. Dissertation, Miinchen, 1910. 
Ramann. “ Mineralstoffgehalt von Baumbliittern zur Tages- und zur 
Nachtzeit.” Jahrb. f. wiss. Bot., 1911, p. 84. 
Ramann & Bauer have investigated, on a large scale, the 
variations of dry weight which occur in the one to four year old 
saplings of a number of trees during the year. They find that 
during the burst of activity following the spring awakening, while 
the leaves are expanding, a loss of 20—45% of the total dry 
weight occurs in the case of deciduous trees. This illustrates in a 
striking way the enormous expenditure of energy involved in 
