284 !> R- CLEVELAND. 



in which to observe the organisms while feeding. She only 

 observed them in the intestinal fluid and in this, as anyone who 

 has ever studied termite protozoa knows, the number of protozoa 

 present is far too great to permit almost any kind of an observa- 

 tion whatever, and, in addition to this difficulty, the protozoa 

 immediately become decidedly abnormal and die very quickly. 

 The best Swezy could do was keep the protozoa alive for six 

 hours, so she states. This investigator also used physiological 

 salt solution to dilute the intestinal contents and states that 

 "the flagellate tends to round up immediately, becoming greatly 

 distended and dissolving a few minutes after being placed on the 

 slide." The osmotic pressure of such a solution is much too 

 high for Trichonympha but not for Trichomonas from the same 

 host. Half this amount of salt is far better. l But better still is: 



NaCl 0.3 grams 



CaCh 0.02 



KC1 0.02 



MgCls o.oi 



NaH 2 PO 4 " o.ooi 



NaHCOs o.oi 



H 2 O 100 cc. 



Loffler's blood serum 0.5 grams. 



This is filtered and used immediately. Instead of the serum, 

 5-10 grams of fresh Termopsis feces may be thoroughly shaken 

 up in the above mixture, and may be used with or without 

 filtering. If filtered, a small amount (1-2 grams) of finely 

 powdered lignocellulose is added. In this way, many Tricho- 

 nympha live ten days and longer and may be observed as con- 

 stantly as desired, under a sealed cover glass or otherwise. 



METHOD OF FOOD INGESTIOX. 



When the flagellate takes in food, the posterior end, owing to 

 contraction of the longitudinal endoplasmic myonemes, becomes 

 invaginated, thus forming a cavity or temporary cytostome (Fig. 

 6). These myonemes, about two micra in breadth and easily 

 observed in living material, are the principal organelles concerned 

 with body movement. They begin very near the anterior tip 

 (somewhere near, possibly within the centroblepharoplast) and 



1 More recent observations show that 0.2 per cent. NaCl is the best salt solution 

 for observing the protozoa of certain tropical termites. 



