CELL-DIVISION IN THE SEX CELLS OF TAENIA 209 
MATERIAL AND METHODS 
The form which I have selected for my studies is Taenia 
teniaeformis (Bloch, 1780) (Stiles and Stevenson, ’05), a ces- 
tode which is a common parasite in the small intestine of the 
domestic cat. Both fixed and live material have been used. 
1. Fixed material 
In order to ascertain whether or not the time of the year has 
any influence upon the character of cell-division or the apparent 
frequency of cell-division, cats were killed every month in the 
year and often three or four times during the month. As soon 
as the host was dead the intestine was opened and the tape worms 
were put into killing fluid. Also to determine whether or not the 
time of the day has any influence upon cell-division, material 
was fixed at all hours during the day from five o’clock in the 
morning until eleven o’clock at night. Some of the cats were 
fed all they would eat for three or four days previous to killing, 
others were starved for the same length of time, and still others 
were killed as soon as they were obtained. This was done in 
order to determine whether or not the food supply has any effect 
on the character of the cell-division. Most often the host was 
chloroformed, but to make sure that the chloroform has no effect 
upon the character of cell-division some cats were stunned by 
a blow upon the head and then bled to death. The character 
of cell-division or the apparent frequency of cell-division did 
not seem to be influenced by the time of the year, the time of 
the day, the amount of food material, or the use of chloroform. 
The following killing and fixing agents were used; sublimate- 
acetic (a saturated aqueous solution of corrosive sublimate, one- 
hundred parts and ten parts glacial acetic acid); picro-acetic (a 
saturated aqueous solution of picric acid one part, distilled water 
two parts, and 1 per cent glacial acetic acid) ; aleohol-acetic (equal 
parts absolute alcohol and glacial acetic acid) ; Flemming’s strong — 
solution; Bouin’s fluid; Gilson’s mercuric-nitric mixture; Carnoy’s 
fluid; and a mixture of Gilson’s fluid and 4 per cent chromic acid 
