426 BOTANICAL GAZETTE [JUNE 
and by WERNICKE (30) in 1895 for several different kinds of seeds. 
Mention may also be made of the work of JARZYMOWSKI (17) in 
1905 with seeds of various economic legumes, and of BoLLey (3) 
in 1912 with those of alfalfa. BotLey obtained positive improve- 
ment in germination if exposure to a given temperature was not 
long enough to kill the embryo. 
Treatment with concentrated sulphuric acid dates from the 
work of Rostrup (25) in 1896-1897. It was also used by ToDARO 
(29) in 1901, by HmTNER (14) in 1902, by JARZYMOWSKI (17) in 
1905, and by BoLtey (3), and Love and Leicury (22) eight years 
later. Increased germination was obtained in all these cases. 
Treatment with other chemicals has included the use of ether, 
ethyl, and other alcohols (VERSCHAFFELT 31, 1912), chloroform, 
sodium hydroxide, postassium hydroxide, potassium nitrate, and 
mercuric chloride. Of these, the lower alcohols are the only ones 
that are very effective. 
There are obvious practical objections, however, to the use of 
either hot water or chemicals. As a consequence, there have been 
numerous efforts to devise means for the mechanical treatment of 
hard-coated seeds. In Germany, Kuntze and Huss (16), working 
about 1890, were able with a scratching machine to increase the 
germination of Lathyrus sylvestris 83 per cent, Vicia Cracca 71 per 
cent, and Astragallus Glycyphyllos 77 per cent. 
Somewhat later MicHatowsk1 devised an apparatus in which 
the seeds were passed between two rollers, one of rubber, the other 
of rough steel. Smaller sorts of seeds were badly crushed by such 
a mechanism, and it was later displaced by two others, one designed 
> the Wissinger Seed Co. , of Berlin, the other, called a “‘ prepara- 
r,’ by H. Nitsson of de experiment station at Svaléf, Sweden. 
a both of these the seeds are thrown from a revolving disk against 
the concave surface of a circular rough stone, within which on 
disk revolves. Hume and Garver (15), using the “ preparator,” , 
obtained a definite increase in the germination of seeds of M edicago 
sativa, M. media, and M. falcata. Another machine now in use in 
England has made it possible, according to CARRUTHERS (7), the 
designer, to buy clover seed guaranteed to germinate 98-100 Per 
cent. The seeds to be treated are fed into a revolving cylinder 
