378 0. C. Glaser and C. M. Sparrow 



In making an application of the osmotic theory two possible 

 factors suggest themselves, and these, operative singly or together, 

 will account for the facts. It is conceivable that when stimulated, 

 the nematocyte suddenly generates heat; it is also conceivable that 

 the cytoplasm around the nematocyst undergoes chemical and 

 physical changes of such a nature that the capsules are enabled 

 to absorb water, and to raise their internal pressures to the explod- 

 ing point. Particularly if heat is liberated at the same time that 

 "dilutation" occurs, this theory offers no insurmountable diffi- 

 culties. The time element need not be considered, for the chem- 

 ical and physical changes which stimulation sets up in a muscle 

 occur very quickly, and when the proper reduction in the concen- 

 tration of the surrounding medium has been made, a nematocyst 

 explodes instantaneously. 



THE PHYSIOLOGICAL EFFECTS OF NEMATOCYSTS ON OTHER 



ORGANISMS 



On the chemical side, it has been shown by Portier and Richet 

 ('02) that an aqueous extract made from twenty-nine of the ten- 

 tacles of a Physalia contained enough poison to kill a pigeon within 

 an hour after injection. Curiously enough no inflammation was 

 set up; irritability and temperature were reduced and diarrhoea 

 frequently set in. These experiments, together with the obser- 

 vation that frogs or fish, when placed in contact with the filaments 

 of Physalia, make no attempts to escape, led Portier and Richet to 

 name the poison involved, hypnotoxin. Very little is known 

 regarding its chemical nature. It is destroyed by a tempera- 

 ture of 55° C; can be precipitated with alcohol; and is non- 

 dialysable. Von Fiirth ('03) who gives a resume of Portier and 

 Richet's work, adds that it is necessary to assume that the nettles, 

 in addition to the hypnotoxin, contain a violent "Reizgift," which 

 accounts for the inflammations, which in spite of the observations 

 quoted above, have been observed in other cases. 



On the physical side, the conclusions of Iwanzoff ('96) and the 

 earlier ones of Mobius ('66), are opposed in certain important 

 respects. Iwanzoff states that the physiological effects of the 



