210 MARY T. HARMAN 
in the proportion of ninety parts Gilson to ten parts chromic 
acid. When a host contained more than one tape worm usually 
two or three killing fluids were used. 
The following stains were used: Heidenhain’s iron-alum-hema- 
toxylin with a counter stain of eosin and without counter stain; 
safranin and gentian violet; safranin, gentian violet, and licht- 
grin; Auerbach’s fluid; alum-carmin and osmic acid; Dela-- 
field’s hematoxylin; and Conklin’s hematoxylin. Although all 
the above stains show nuclear structure, the combination which 
shows centrosomes and spindle fibers best is Heidenhain’s iron- 
alum-hematoxylin without counter stain, following a fixation in 
Flemming’s strong solution. " These structures were more clearly 
visible when, before being stained, the sections were bleached 
twenty-four to forty-eight hours in turpentine at a slightly 
elevated temperature. 
After fixing, the tape worms were cut into pieces, each contain- 
ing from two to twenty-five proglottids, depending upon the 
size of the tape worm and the size of the proglottids. ‘Two entire 
tape worms, a small one indicating that perhaps it was young 
and a large one probably older, were sectioned. Of the others, 
pieces at intervals of four to twenty-five proglottids were sec- 
tioned. The sections were cut 3 » thick. Some sections were 
cut cross and others sagittal. The pieces not sectioned were 
preserved in 85 per cent alcohol and saved for further reference. 
The character of cell-division was found to be the same both in 
the large and the small worms. 
2. Living material 
At two different times I made observations on living material, 
believing with Richards that ‘‘for amitosis there is but one abso- 
lutely certain criterion, the observation of living material and 
subsequent study of fixed material under observation” and with 
Child that a real demonstration of the occurrence of amitosis 
is impossible in fixed material. 
I found by experiment that Taenia teniaeformis, when placed 
in Ringer’s solution and kept at a temperature of 39°C., will 
live outside the body of the host forty-eight hours or more. 
