450 



MY GARDEN. 



young trout. Belonging to this tribe, we have abundance of the 

 Cyclops quadricornis (figs. 997 and 998), which are interesting creatures 

 to watch in an aquarium. We have also the Daphnia Pulcx (fig. 999), 

 which is common everywhere. 



FIG. 997. Cyclops quadricornis, 

 magnified. 



FIG. 998. Ditto, side view, 

 magnified. 



FLEAS. 



FIG. 999. Daphnia Pnlex, 

 magnified. 



There are many species of Fleas. One species infests the dog, 

 another the cat, and most birds have their particular flea ; but of all 

 the many species it is remarkable that the one which lives upon the 

 mole, the Pulex talpce, has no eye. The larva of the Pulex irritans, 

 the bite of which drives some persons almost mad, is propagated by 

 egg. The larvae of the flea live upon filth or in the nests of birds. 

 According to Cuvier, in about ten days after birth they spin a silken 

 shell, and in another ten days emerge in a perfect state. The fleas on 

 the creatures in our garden might alone constitute a long study. 



PARASITES. 



The remarkable book of Denny has taught us how 

 many Parasites there are upon our birds and animals, 

 and even upon man. Denny has pointed out that the 

 same species may live upon many birds. I have many 

 kinds in my collection, and have figured one as an 

 example, the Parasite of the Ox (fig. 1000) ; but species 

 may be found on nearly every living creature, and on 

 some creatures more than one kind. 



FIG. looo. Parasite 

 of the Ox, mag- 

 nified. 



