ARTHROPODA 



Fig. 132. 



29s 



Fig. 132. The American Lobster (Homarus americanus). From Herrick. 



Questions on the figure.^What body-regions are distinguishable in the 

 lobster? Compare by actual measurement the size of the crushing claw with that 

 of the body. How many segments in the abdominal region? Compare with 

 Pig. 130. 



as one hundred million lobsters have been taken in a single year in Canadian waters 

 alone. There is no doubt that the lobster is in immediate danger of extinction as 

 a food animal, as is shown by the fact of greater difficulty in obtaining them and 

 by the decrease in the average size of the animals put on the market. This de- 

 crease occurs in the face of the fact that the mature female produces from ten 

 thousand to one hundred thousand eggs. These are carried under the abdomen 

 of the mother until hatched, which requires a period of ten or eleven months. 

 After hatching the young undergo a series of moultings during which time they 

 are the prey of many kinds of enemies. Such is the mortality that, on an average, 

 not so mam- as two of all the yovmg of a female reach maturity. This is another 



