32 STUDIES IN ANIMAL LIFE. 



question here, let us merely note that the Monosto- 

 mum, into which the Cercaria will develop, produces 

 eggs, from which young will issue ; the second gen- 

 eration is not produced from eggs, but by internal 

 budding; the third generation is likewise budded 

 internally, but it, on acquiring maturity, will pro- 

 duce eggs. For this maturity, it is indispensable 

 that the Cercaria should be swallowed by some bird 

 or animal ; only in the digestive tube can it acquire 

 its producing condition. How is it to get there ? 

 The ways are many ; let us witness one : 



In this watch-glass of water we have several Cer- 

 carice swimming about. To them we add three or 

 four of those darting, twittering insects which you 

 have seen in every vase of pond- water, and have 

 learned to be the larvae or early forms of the 

 Ephemeron. The Cercaricz cease napping the water 

 with their impatient tails, and commence a severe 

 scrutiny of the strangers. When Odry, in the riot- 

 ous farce Les Saltimbanques, finds a portmanteau, he 

 exclaims, ".Un mallei ce doit etre d moil" ("Surely 

 this must belong to me!") This seems to be the 

 theory of property adopted by the Cercaria: "An 

 insect! surely this belongs to me!" Accordingly 

 every one begins creeping over the bodies of the 

 Ephemera, giving an interrogatory poke with the 

 spine, which will pierce the first soft place it can 

 detect. Between the segments of the insect's armor 

 a soft and pierceable spot is found ; and now, lads, 

 to work! Onward they bore, never relaxing in 



