tort] CURRENT LITERATURE 315 
worthia is thought to strengthen the evidence of the approximation of Arauca- 
rineae and Abietineae in the early Mesozoic, and of the more primitive character 
of the latter. 
The same investigator has also published a new species of Prepinus from 
the Cretaceous of Martha’s Vineyard, which differs from the type species of 
Staten Island in that the wood of the short shoots has numerous resin canals 
in two or more rows, and the pith is without sclerotic nests. The conclusion 
is reached that “igneous resin canals” are features of the oldest Abietineae, 
as shown now by the structure of the archaic genus Prepinus and also by that 
of the oldest species of Pityoxylon—J. M. C. 
Chlorophyll and photosynthesis.—IrviNG,*> working in BLACKMAN’S labo- 
ratory, has studied the relation between the early development of chlorophyll 
and of the photosynethetic power. He finds that seedlings developing in 
darkness and later transferred to light, or developing from the first in light, 
are able to fix all CO, produced by respiration only after becoming almost 
fully green. When considerable photosynthetic power does appear, it develops 
rapidly. The author believes the photosynthetic activity up to this stage 
never fixes more than ro per cent of the CO, produced by respiration, and never 
amounts to over 1 per cent of the activity after the full development of the 
chlorophyll. The following quotation from the summary shows the signifi- 
cance of the work: “We are forced to conclude that the first development of 
this function is not in any relation to the amount of chlorophyll produced, 
and that the amount of chlorophyll present is never a limiting factor to assimi- 
lation in these early stages of the assimilating organs. If this is so, then it 
must be some other component part of the photosynthetic machinery which 
controls the beginning of complete functional activity. This part is not 
developed by illumination so quickly as the green pigment is developed, and 
therefore the pigment, and other parts of the total machinery, lie idle at the 
Stage we have examined, awaiting the developing of the last factor.” —WILLIAM 
CROCKER, 
€duction divisions of Oenothera.—Davis* has published another con- 
firmation of the earlier work of Gates” and of Grerts* on reduction in 
nieces 
_ 4 Jerrrey, E. C., A new Prepinus from Martha’s Vineyard. Proc. Boston Soc. 
Nat. Hist. 34:333-338. pl. 33. 1010. 
** IRvING, A. A., The beginning of photosynthesis and the development of chloro- 
pPhyll. Annals of Botany 24:805-818. 1910. 
* Davis, B. M., The reduction divisions of Oenothera biennis. Annals of Botany 
24°031-651. pls. 52, 53. gto. : 
“ Gates, R. R., Pollen development in hybrids of Oenothera lataXO. Lamarcki- 
“na, and its relation to mutation. Bot. GAZETTE 43:81-115. pls. 2-4. 1907- 
~——-, A study of reduction in Oenothera rubrinervis. Bot. GAZETTE 46: 1-34. 
pls. I~3. 1908, ‘ 
ae ca The behavior of the chromosomes in Oenothera lataXO. gigas. 
ETTE 48:179-199. pls. 12-14. 1900. ; 
es Graurs, 7 M. atest i [oak der Cytologie und der partiellen Steri- 
litét von Oenothera Lamarckiana. Recueil Trav. Bot. Néerl. 5:93-208. 1900. 
Bort. 
