476 BOTANICAL GAZETTE [DECEMBER 
Miss MAtTTHAEI’? has made a careful study of the effect of temperature on 
photosynthesis, which by avoiding radical sources of error corrects the resul s of 
various observers and particularly those of KrEUSSLER, which have been accepted 
and quoted for more than a decade. Having found that the actual temperature | 
of a leaf was not that of the water bath within which it was placed when high 
intensity of light was used, thermoelectric measurements of temperature became 
necessary. A thermocouple of copper and constantan wires only .o87™™ in 
diameter was imbedded in the midrib of the leaf used and was connected with 
a galvanometer to which also a second thermoelement in a water bath was con- 
nected. When this bath was brought to such a temperature that there was no 
deflection of the needle the temperature of the element in the leaf was known. 
The results show that corresponding to each temperature there is a definite 
maximal amount of photosynthesis which cannot be reached unless both light 
and CO, supply are adequate. These maxima increase with increasing tempera- 
ture, forming a curve convex to the temperature abscissas which resembles the 
respiration-temperature curve. They begin to decrease suddenly some degrees 
below the temperature which can be endured only a few hours. The maximum 
photosynthesis at any temperature can be maintained only for a short time, 
declining the sooner the higher the temperature. The difficulties overcome in 
the experimentation and the manipulative skill exhibited make this a notable 
contribution to plant physiology.—C. R. B. 
Kuyper’* has given an account of the events of the development of the asco- 
carp of Monascus purpureus Went and M. Barkeri Dangeard. The account of 
the former agrees in the main with that recently given by Ikeno,3° but differs in 
some respects. The sequence of events is as follows: The ascogonium consists 
of two cells, the lower of which develops. No fusion was observed between the 
ascogonium and pollinodium. The number of nuclei in the ascogonium increases. 
“Free cells” are then formed possessing one to several nuclei. The 1-nucleate 
Stage is regarded as having arisen from the fusion of the nuclei of the originally 
binucleate cell, a view opposed to that of IKENO, who believes the cells to appear 
with single nuclei. In the next stages the number of nuclei in each free cell 
increases to a considerable extent. It appears that the spores are now formed 
within the free cells. These are represented as containing a variable number of 
nuclei, one to many, so that the whole spore is deeply stained. According to 
IKENO each spore contains but a single nucleus while the other nuclei of the free 
cell degenerate. When mature the spores fall apart and come to lie free in the 
37 MATTHAEI, GABRIELLE L. C., Experimental researches on vegetable assimila- 
tion and respiration. III. On the effect of t perat carbon-dioxid imilation 
Phil. Trans. Roy. Soc. London B. 197:47-105. figs. 6. 1904. 
38 Kuyper, H. P., De perithecium-ontwikkelung van Monascus purpureus Went 
en M. Barkeri Dangeard in verband neet de phylogenie der Ascomyceten. Disserta- 
tion. pp. 148. Amsterdam. 1904. 
39 IKENO, Ueber Sporenbildung etc. Ber, Deutsch. Bot. Gesells. 21:250. 1903+ 
