ene 
8 BOTANICAL GAZETTE. ° | January, 
I will describe the imbedding method as employed in 
ous ways. The primary roots of germinatin 
Vicia Faba, or the secondary roots of the bulb of Allium — 
Cepa (grown in water) should be taken for this purpose, for 
in these large and beautiful karyokinetic figures are with — 
certainty to be found. In the roots of Phaseolus multiflorus, 
Zea Mays or Aésculus Hippocastanum, on the contrary, these 
figures are small and indistinct. 
Fresh tips of roots, 1 or 2 centim. long, are conveyed 
into a sufficient quantity of a reagent calculated to arrest 
living protoplasm in its original form. Several substances 
may be employed in our case. I obtained very good results 
with a watery solution of chromic acid (1% ), with.a saturated. 
solution of picric acid, etc. ; but absolute alcohol must not b 
applied, as not enly the roots are totally shriveled in thi 
fluid, but moreover, because, as has already been observed 
it is often difficult to permeate objects thus treated with par- 
alin. The most beautiful specimens, however, were obtaine 
from roots which had been immersed for some time in Flem 
ming’s Mixture slightly altered. We will suppose that suc 
& liquid is used, viz.: a watery solution containing chromic 
acid 1%, osmic acid 0.02%, and acetic acid 0.1 %. Mixtures 
containing more osmic acid are to be preferred, especially 
the karyokinetic figures are to be studied. As, however, 4 
larger amount of osmic acid or the same amount combined 
with less chromic acid is apt to cause some difficulty in the 
imbedding, at least for beginners I advise to employ the mix-_ 
ture here recommended. It the karvokinesis is to be 
studied, it will be advisable to remove on both sides of the 
root-tip a slice of tissue in order to facilitate the entranee of 
the reagents. 
ae this mixture the root-tips remain from twenty-four t0 
forty-eight hours, and then, the protoplasm being fixed, the 
acids are washed out in running water. For this purpose 
they are put into a vessel, with a double perforated cor 
Sy de pee a funnel for receiving a jet of water, anc 
econd orifice a rever a i 
to the bottom of the lo 9 rig ingens. 
these means the roots 
sh water, and after this time it may 
asserted that the acids have been thoroug! 
“Suggested by Prof. Pekelharing. faa 
= 
confidently 
