364 BOTANICAL GAZETTE [MAY 
millimeter classes showing the frequencies 1, 6, 5, 8, 4, 5, 2, I, is grouped in a 
ratio of 7 wide :17 medium :8 narrow or nearly the expected 1:2:1. Every 
variation curve of purely chance variates can be arranged in this way by counting 
one-fourth of all the variates from each extreme, leaving the group between 
the quartiles as the 50 per cent. intermediates expecte 
The author reaffirms in a general statement the ealuseen offered in his 
first paper,'? to account for the appearance of certain nova; but makes an inter- 
esting observation in disagreement with that explanation, apparently without 
noting the discrepancy—the new character of the pigmented parent which 
was changed to the active state by crossing. He now states that he could 
occasionally observe the mottled pattern like a faint water mark in the white 
arent, and its occurrence there makes this an excellent new evidence that the 
mottled character is not latent in the usual sense of being inactive, and that 
it is not present in the pigmented parent, but being possessed by the white 
parent is simply invisible owing to the lack of pigment.—GEORGE SHULL. 
Spraying potatoes——Strewart, Eustace, and Srrrinr?° have published 
the extensive results secured by them during 1904 in their seties of experiments 
in the prevention of potato diseases by spraying. The results secured during 
previous years should ‘be read in this connection.2? During 1904 a total of 
of the Experiment Station at Geneva, while the remainder were conducted as 
“farmers’ business experiments” in various parts of the state. The experi- 
ments at Geneva form a part of a ten-year series of experiments designed to give 
average results for various seasons. The other experiments should yield valuable 
data year after year as to the actual net gains to be expected from the spraying 
against potato diseases under actual farm conditions. At Geneva five sprayings 
increased the yield 233 bushels per acre, while a gain of rg1 bushels was secured 
from three sprayings. This gain was mostly due to the longer growth of the 
plants made possible by the prevention of the late blight and the rot which follows 
it. In the business tabu covering a total of 180 acres, the net gain per 
acre due to spraying was $24.86. The average loss from blight in New York 
State during 1904 was not less than 60 bushels per acre. The sugyestion is made 
that the community hire some person to do all their spraying, thus effecting a 
saving of time and labor—E. Mrap Witcox. 
Alternation of generations in Phaeophyceae.—Strasburger?? agrees with 
OLTMANNs that there is no alternation of generations in the Phaeosporeae. He 
19 See Bor. GAZETTE 39: 303-304. 1905. 
20 Stewart, F. C., Eustace, H. J., and Srrrine, F. A., Potato spraying experi- 
ments in 1904. Bull. N. Y. Geneva Exp. Stat. 264:93-204. pls. I-16. I map. 1995. 
2t Potato es experiments in tg02. Bull. N. Y. Geneva Exp. Stat. 221: 
235-2063. 1 
Sendi apeaion experiments in 1903. Bull. N. Y. Geneva Exp. Stat. 241. 1903. 
22 STRASBURGER, oes Zur Frage eines Generationswechsels bei Phaeo- 
phyceen. Bot. Zeit. 64:1~7. 1906. 
