314 BOTANICAL GAZETTE [APRIL 
times its original size, the chromatin remaining in one place, while the rest of 
the nuclear cavity is occupied only by the sap. A complete series of measure- 
ments shows that the chromatin area has not diminished. Although there is 
no contraction, important changes take place in the chromatin during synapsis. 
There is some evidence that the reticulum of the resting nucleus is composed 
of a number of threads, and that this number corresponds to the diploid num- 
ber of chromosomes. Further, the threads are double and there is no evi- 
dence of any blending or fusion, the actual reduction occurring much later 
than the period known as synapsis. A paper dealing with the details of 
reduction is to follow.—Cuartes J. CHAMBERLAIN. 
Turgescence and respiration.—MAIGE and NIcoLAs” have performed some 
very interesting experiments upon the effect of turgescence upon respiration. 
The materials used were various buds, leaves, and embryos. The gas deter- 
minations were made by the Bonnier-Mangin method. The work is reported 
under three heads: effect of increase of turgescence, effect of decrease of 
turgescence, and effect of a decrease followed by an increase. A rise in tur- 
gescence is always followed by increased production of CO,, intake of O2, and 
an increase in the ratio CO,/O,. A fall in turgescence produces similar but 
less marked effects in material taken directly from the plant or soaked for a 
period in 5 per cent sucrose. In material previously soaked in 10 oF 20 per 
cent glucose, this treatment always gives a decrease in CO,, O., and frequently 
in the CO./O,. Each change, in the decrease followed by the increase, 8¢0~ 
erally gave an increase in CO,, O2, and CO,/O.. These facts are new and m 
interesting, but the interpretations will not find universal acceptance. The 
authors believe that increased turgescence increases respiration by increasing 
growth; and decreased turgescence by concentrating the oxidizable solutes 
of the cell. The first stimulative effect they consider the greater. e 
authors postulate an optimum concentration for the oxidizable solutes of the 
cell, and attribute the reversal of behavior after treatment with the strong 
glucose solutions to this optimum being passed.—WILLIAM CROCKER. 
New mesozoic plants.—JEFFREY% has described a new araucarian genus 
(Woodworthia arizonica) from a triassic forest of Arizona. The wood is of the 
Araucarioxylon type, but the short shoots are abietineous, and persisted in the 
wood of the trunk throughout the life of the tree. It is suggested that short 
shoots characterized the older coniferous stock, and that this would fit into the 
current explanation of the coniferous ovuliferous scale as a modified short 
shoot. The leaf traces did not persist in the secondary wood, as they do 
the living araucarians, but JEFFREY does not regard persistent leaf traces as 
an ancestral character of the coniferous stock, as SEwARD and LIGNIER have 
claimed, but as a more recently acquired character. The testimony of Woot 
de la 
1910. 
* MatcE, A., et Nicotas, G., Recherches sur l’influence des variations 
turgescence sur la respiration de la cellule. Rev. Gén. Botanique 22:499-42- ae 
__ ) Jerrrey, E. C., A new araucarian genus from the Triassic. Proc. Bostop °° 
Nat. Hist. 34° 325-332. pls. 31, 32. 1910. 
