REPORT OF COMMISSIONERS OF INLAND FISHERIES. 45 



alive and under practically normal conditions. Although a few of 

 the observations recorded resulted from a study of individual lobsters 

 in successive stages, the greater body of facts was drawn from the 

 study of large numbers of individual lobsters taken at random from 

 among the thousands of their fellows in the large canvas bags, or, in 

 the case of older specimens, from the storage cars. Insomuch as 

 the present methods for hatching and raising allow a considerable 

 range in water depth (from surface to three feet), in light and shade, 

 in temperature and food supply, it is safe to conclude that prac- 

 tically normal life conditions are secured, and that these give rise to 

 normal conditions in the development of the young larvae. The 

 course of the observations includes the following considerations: 



1. What are the morphological changes that take place in the 

 successive stages of the lobster? 



2. What is the nature of the pigmentation of the lobster, and 

 what are the color changes in the successive stages? 



A few preliminary statements may be found necessary. 



The life of the lobster from the time of hatching to the time of 

 death is, it may be said, but a series of "stages" so-called, each one of 

 which represents a period of its life between any two successive moults 

 or castings of its shell. Of these stages the first four are passed 

 through rapidly, the young creature moulting usually four times in 

 the first twenty days of its existence. It is these first few stages, so 

 quickl}'- passed, which include the most important of the changes 

 that the young lobster undergoes, and these are called the larval 

 stages, denoting the successive emergence of one form from another. 

 In each successive emergence the young lobster is larger than before; 

 thus we can say he grows by moulting, but never grows between 

 moults. From the fourth stage on, however, each succeeding stage- 

 period is of longer interval (aged lobsters probably not moulting 

 more than once in several years), and the changes which the young 

 adult, as he is now called, undergoes are correspondingly less dis- 

 tinct or significant, being manifested chiefly in the various color 

 changes and in those alterations in the internal morphology which 



