E1906] CURRENT LITERATURE 77 
4 They find+* an enzyme in spermatophytes and pteridophytes generally, which 
| decomposes H,O, energetically, with the evolution of O,. When this enz zyme 
4 is destroyed or its action inhibited, the chlorophyll is quickly destroyed and the 
| plant bleached. They also demonstrated the formation of formaldehyde (when 
_ its prompt condensation was prevented) in the immediate vicinity of the chloro- 
_ plasts. The usual condensation of the HCOH is due, they hold, to the proto- 
a plasmic stroma of the chloroplast and not to an enzyme; yet the experiment on 
4 which they rely is not conclusive on this point.—C. R. B 
Seeds of Euphorbiaceae —A study of the development of the seeds of numer- 
_ ous genera and species of Euphorbiaceae has given SCHWEIGER#? the following 
results: The obturator, a tissue which serves for the conduction and nutrition 
_ to the seed. The tip of the nucellus is often much elongated, and until fertili- 
4 zation is effected is often in direct connection with the obturator. The caruncle 
‘ belongs to the seed, is developed from the outer integument, and serves to 
_ Separate the seed from the placenta.—CHarLEs J. CHAMBERLAIN. 
q Zygospores of Mucor.—According to HaMaxkErs° the production of zygo- 
Spores of Mucor stolonifer, with proper conditions of moisture and temperature, 
_ is dependent only upon the nature of the substratum. The atmosphere should 
_ be saturated with moisture and the temperature about 70° F. The substratum 
_ used is corn muffin bread, which the baker makes after the following formula: 
corn meal, 16 pounds; flour, 3 pounds; lard, 3 pounds; salt, } pound; eggs, 
_ 48; sweet milk, 3 gallons; baking powder, 18 ounces. In a large proportion of 
_ cultures zygospores appear in five to seven days.—CHARLES J. CHAMBERLAIN. 
Germination of pollen—Josr has succeeded in germinating the pollen 
grains of various grasses,5' which have heretofore proved refractory, by growing 
_ them under conditions where they can obtain water very slowly from the medium 
by which it is held. Thus, a starch paste made with only one or two parts of 
water proved useful; and also parchment. paper soaked with a sugar solution. 
tag pollen grains of certain Compositae have also ont to the latter treatment, 
ut none of the Cichoriaceae or Umbelliferae —C. R. B 
on 
4 Usuer, F. L., and Prrestiey, J. H., A study of the mechanism of carbon 
_ assimilation in green ‘phe, Proc. Roy. Soc. London B. 77: 369-376. 1906. 
ScH R, JOSEPH, Beitrige zur Kenntniss der Samenentwickelung der 
’ Sirah ec on 94: 339-379. 1905. 
a S° HAMAKER, J. I., A culture medium for the zygospores of Mucor peso 
Becience N. S. 23:710. 1906. 
. he oe L., Zur Physiologie des Pollens. Ber. Deutsch. Bot. Gesells. 23:504- 
15. 
