360 BOTANICAL GAZETTE [NOVEMBER 
location or outline of the bundle was wanted, the cross-sections were 
cut 20 to 30 # thick; in other cases they were cut 10 # thick. Longi- 
tudinal sections were cut at right angles to the inner surfaces of the 
cotyledons, as well as parallel to that plane; these were cut 10 # thick. 
Staining was done on the slide with safranin and Delafield’s hema- 
toxylin, or safranin and anilin blue. Other stains were tried, but 
these two combinations gave by far the best results. A few speci 
mens were killed by the general picro-mercuric-chlorid method, but 
no advantage was gained. 
Where seedlings were required, the hard coats of the seeds were 
cut partly open at the micropylar end, and the seeds placed on one 
side, partially pressed into moist earth, in a flower pot, and put na 
warm moist place in the greenhouse and kept well watered. A good 
many seeds had been planted three years before and had grown to 
considerable size, some of them having a stem 1oo™™ in length and 
25™™ in diameter, and bearing several leaves. These were treated 
about as the embryos, except that all the specimens were cut into 
lengths of 15 to 20™™, Of course the greater the size of the plant 
the more slowly the processes of killing, washing, embedding, etc., 
were conducted. Especial care had to be taken in imbedding the 
larger specimens, the best results being obtained when they vor 
carried through the process of penetration with paraffin for a whole 
month. After this time they could. be cut with an ordinary Minot 
rotary microtome with perfect ease, and the sections could be held in 
complete ribbons. After this precaution, ribbons were obtained from 
specimens 26™™ in diameter and cut 10 thick. Staining was = 
as before with safranin and Delafield’s hematoxylin, or safran gis 
anilin blue, the former combination giving the most satisfactory 
results. An enormous amount of labor is necessary and in 
much care to keep sections of entire plants in serial order, both 
cross and longitudinal sectioning, but it is the only satisfactor) 
method 
In order to obtain the details or to follow up the leaf trace course 
every section was examined, from the first to the last, and ¢ fully 
drawings made of ev ery second or third section. These re jons 
numbered and kept in series and later compared, and recons see 
were based upon them. 
