220 The Botanical Gazette. (June, 
leaf. The time required for the full development of the leaf 
is one and a half to two months, or from the first of May to 
the middle or latter part of June. A goodly amount of each 
collection was dehydrated in Schultze’s dehydrating appa- — 
ratus and then put in absolute alcohol. In connection with 
the material as above described a large part of each collection 
intended for coarser work was placed directly in alcohol. In 
addition to the supply of alcoholic material a number of 
young thrifty sprouts were taken from the woods in Septem 
ber and placed in pots in the green-house with the hope of 
at least inducing an early development of leaves for histo 
logical and dynamical study. This experiment was quite 
successful and leaves both on the old branches and on new 
shoots sent up from the roots afforded ample supply of mate- a 
rial throughout the latter part of winter and early spring for 
all necessary purposes. The young sprouts developed from — 
the roots were the ones on which the observations on leaf E 
movement as above described were made. The observations — 
were not made, however, until after the leaves had attaim 
almost if not entirely their full development. I also - 
took to secure growing material from seeds, but on accoult — 
of defects in the seed obtained the experiment was unsuc- 
cessful. ‘bed 
In the imbedding work, the paraffin method as ari = 
by Moll> of Groningen, Holland, was used. It was, ae r 
ever, found necessary to modify the method in some 7 a 
house supply and hardened in picric or chromic acid abet 
best results. Very little staining was done, a ate 
ollet- 
The mature pulvinus is composed of parenchy rs probably : 
* The application of the paraffin imbedding method in botany: 
Gazette 13: 5. 1888. 
