154 Rhodora [SEPTEMBER 
just described and found that somewhat better specimens could be 
obtained, though not so quickly, by using ordinary driers in combina- 
tion with the corrugated ventilators: a drier was placed over the 
ridged face of each board, so that the sheet containing the specimen 
lay between.a drier on one side and the smooth face of a ventilator 
on the other. This scheme was essentially the one used in the field 
by Professors M. L. Fernald and K. M. Wiegand, “except that one 
change of driers was made in order to straighten folded leaves, etc.” 
(l. c., p. 223). It was found that such a press could be left without 
attention for several days, even in a humid climate. Finally, Collins 
suggested the practicability of using various sources of heat other 
than the lamp, such as an oil stove, electric heater, cook stove, steam 
radiator, ete. 
Three years later Ricker,' in a government circular designed pri- 
marily to instruct novices in the preparation of presentable botanical 
specimens, recommended the use of corrugated boards in combination 
with driers for pressing, advising that the specimen sheet be separated 
from the ventilators on both sides by driers. He recommends double- 
faced (d. f.) boards, i. e. boards with both faces covered and smooth, 
in preference to the single-faced type, and stipulates that the corruga- 
tions should run lengthwise the board. Regarding the use of the d. f. 
board Collins (l. ¢., p. 223) was of the opinion that although “it is 
better to handle, and can be used either side up, it appears doubtful 
at present if it has any particular advantages otherwise over the single- 
faced.” 
The primary object of the present paper is to proclaim the advan- 
tages of the d. f. board ventilators, and to describe briefly our experience 
in using them under diverse conditions, with the hope that others may 
profit by our results. During the summer of 1915 and again in 1916 
the senior writer spent about two months in ecological investigations 
in northern Cape Breton.? As a desirable adjunct to these studies 
considerable attention was devoted to the flora of the region, and some- 
thing over 2000 sheets of vascular plants were prepared. For pressing 
and drying, d. f. corrugated boards, cut with the corrugations running 
lengthwise, were used, driers being omitted except with occasional 
1 Ricker, P. Z. Directions for collecting plants. U. S. Dept. Agr. Bur. Pl. Ind. Cir. 126. 
pp. 27-35. f. 1-6. 1913. 
2 See Nichols, G. E. The vegetation of northern Cape Breton Island, Nova Scotia. Con- 
necticut Acad. of Arts & Sciences 22: 249-467. f. 1-70. 1918. 
