allowing the object to b 
10 BOTANICAL GAZETTE. { Janu 
another of 2.2 and 5 centimeters. Both havea heigh 
wetted with turpentine, to prevent the parathn from 
hering to their surface, and then melted paraffin is p 
into the rectangular space till it is nearly filled 
root-tips have all this while remained in the drying- 
but now they are taken out and put into the paraftin fillin 
the mould. If this was somewhat over-heated when th 
operation began, and needles heated in the flame 
employed, there will be ample time for arranging the tt 
tips in the directions required before the paraffin cools. | 
objects will not stick to the bottom of the mould, because 
paraftin here hardens almost instantaneously on coming 
contact with the cold surface of the metal. As soon a 
molten mass has cooled so far as to be covered with : 
film on its upper surface, cold water should at one : 
poured over it, for which purpose the whole apparatu 
placed from the beginning in a flat basin. 
This sudden hardening of the paraffin serves to pr 
the formation of cavities in it, which otherwise will so 
times occur and make it impossible to obtain good sec 
now proceed to the section-cutting, which shoul 
in thi se with a microtome. Thus only 
the advantages of the imbedding method be fully en) 
eries Of consecutive sections is 
18, if transverse, will most beautifully exhibit the wl 
process of development going on in the root-tip, and if] 
gitudinal it will be very easy and save much labor to § 
rom the series one or a fey sections which have p 
r 
scientific instrument company, I selected an instrument ¢ 
2 Principles, Caldwell’s microtome 
beyond my means, and the so-called rocking microtom 
€ Moved in the three directions 
Space. This, however, is often necessary in making sec 
* Of late, however. I have become m t with some I 
it wonld be possible toe mplo € more and more convinced that ith soe 
¥: the rockin, . Schinland’s eX 
fl: ©.) has Sreatly strengthened this conviction ome wat. Dey Be 
