1916] CURRENT LITERATURE 325 
both are smooth. In no case does segregation in the second or third hybrid 
generation result in spikelets with the first glume smooth and the second 
pubescent 
It is not easy to accept a hypothesis which limits the operation of a Men- 
delian factor to one of two identical and adjacent morphological structures, 
nor to believe that the character of pubescence is in the case of one of these 
Structures due to a dominant and in the other case to a recessive factor. 
Furthermore, unless the reviewer has failed to comprehend the data, a much 
simpler hypothesis will account for the situation. Let us postulate a single 
dominant factor for the glume pubescence; this factor is linked with the factor 
for black glumes. A second factor, linked with the factor for “cultivated” 
base, may be conceived of as a partial inhibitor of the pubescence factor. 
In accordance with the idea of position effect, it would operate most power- 
. could be manifested only by blacks, one-fourth of which would appear, in 
accordance with expectation, fully pubescent on both glumes. It appears 
to the reviewer that these considerations apply to the numerical data as well 
as one could expect 
The cross-overs detected by SURFACE were exceptions to the linkages 
between the factors for pubescent glumes and black (about 0.7 per cent), and 
the inhibitor of glume pubescence and the factor for “cultivated” base (about 
I.5 per cent). 
It seems unfortunate that the author has not used the conventional 
terminology of the grass inflorescence in his otherwise exceedingly well pre- 
sented paper. Although he defines his terms, the paper is a long one, and if 
merely glanced over, the unusual terminology might be perplexing if not 
ding. ‘Head” is used for panicle; ‘“‘grain” for the caryopsis with its 
adhering lemma and palea; “pedicel of lower grain” for the portion of the 
rhachilla between the two fertile florets; “pedicel of upper grain” for the por- 
tion of the rhachilla above the second floret; “flowering glumes”’ for the flower- 
ing glume and Jemma of the same floret; ‘dorsal side of grain” for the lemma; 
“ventral side of grain” for the palea——H. H. BARTLeTr. 
ohesion of water and the rise of sap.—From theoretical considerations 
RENNER? draws the following important conclusions: (1) The vapor pressure 
3 RENNER, O., Theoretische und Experimentalles zur Kohisionstheorie der 
Wasserbewegung. Jahrb. Wiss. Bot. 56:617-667. 1915. PrEFFER’s Zeitschrift. 
