202 VENOMOUS SNAKES AND THE PHENOMENA OP THEIR VENOMS 



Other kinds of spermatozoa which are acted upon in much the same manner 

 as the two examples given are those of the following orders and species: 



Pisces: Fundulus heteroclitus (minnow), Cyprinus carpio (German carp.) 

 Arthropoda: Homarus ameriamus (lobster), Eupagurus longicarpus (small 



hermit-crab), Eupagurus pollicaris (large hermit-crab), Limulus poly- 



phemus (horse-shoe crab), Libinia (spider-crab). 

 Vermes: Cirratulus grandis, Lepidonotus squamatus (scale-worm), Lum- 



briconereis opalina, Nereis virens (clam-worm). 

 Echinodermata: Asteria vulgaris (star-fish), Arbacia punctulata (purple 



sea-urchin). 



The following kinds of spermatozoa are found to be wholly refractory to 

 the effect of venom, even cobra: Phascolosoma among the vermes, and 

 Pentacta frondosa (sea-cucumber) among the echinodermata. 



Egg cells : For the study of ovolysis the egg cells of several orders of cold- 

 blooded animals were employed: pisces, arthropoda, vermes, and echinoder- 

 mata. Not all of these cells are affected equally, and some are not acted on 

 at all. In some instances pigmented ova, under the influence of venom, give 

 up their pigment, which is diffused along with other interior contents into 

 the surrounding medium, tinting this so as to suggest the liberation of haemo- 

 globin from red blood-corpuscles by venom and other hsemolytic substances. 



Table 15 illustrates the changes in unfertilized eggs brought about by venom. 



The experiments prove the susceptibility to venom cytolysis of certain ova of 

 cold-blooded animals. Of the ova tested, those of Limulus and Nereis failed 

 to show distinct changes leading to more or less complete dissolution. Among 

 other susceptible ova are those of Phascolosoma and Cirratulus, with which 

 may be mentioned the fact of the insusceptibility of sperm cells of the former 

 worm under the same conditions of venom treatment. (Plates 30 and 31.) 



Table 15. 



