842 . Scientific News. [ October, 
escape distortion during the further treatment. Care must be 
taken that the embryonic area remains moist. Drop on two drops 
three minutes until a slight browning is produced, wash off again 
with distilled water, strain with picrocarmine, which dyes the blas- 
toderm after a variable time according to the intensity of the 
osmic acid action. The next step is important because it stops the 
further darkening by the osmium, which otherwise injures or 
ruins the specimen. Pour Miiller’s fluid, or 0.5 per cent. chromic 
acid solution on the slide and leave it over night. The next 
morning the blastoderm is ready for dehydration by alcohol, and 
mounting in the usual manner in balsam, or better in three parts 
pure Canada baisam mixed with one part d’Ammar varnish, as 
furnished by the microscopical dealers, 
Embryos mounted in this way make very perfect preparations, 
surpassing, indeed, those otherwise treated. 
vat 
VV 
SCIENTIFIC NEWS. 
— The method of teaching elementary botany at the Michigan 
Agricultural College, by Professor W. J. Beal, seems to us to D& 
so excellent, that we extract the following reference to it in his 
“ Before the first lesson each pupil is given some specimen to 
study. If flowers or growing specimens cannot be had, 4 
each a branch of a tree or shrub, which branch may be two fee 
long. The examination of these is made during the usual time 
for preparing lessons, and not in the class room. Without ye) 
the specimen in sight, they are to tell what they can about t Pid 
for the next recitation. They can use books if they pres” 
and the hour is mostly spent in hearing different members rep - 
their discoveries, until all have had a chance to add anything ne 
noticed by any other member. The teacher suggests a few ere 
points for study. The pupils are not told about things ban 
they can see for themselves. An effort is made to keep fue 
working after something which they have not discovered. I ' 
members disagree on a point, on the next day, after further ree a 
ey are requested to bring in all the proofs they can to sus 
their separate conclusions. ‘ d by 
“It is often astonishing to notice how much is discovere@ 
so many good eyes. For the next lesson the students revie™, 
first lesson, report on a branch of another kind of pea soni 
they have studied, and notice the points of difference an sis 
