THE AMERICAN LOBSTER. 



53 



A graphic representation of the fecundity of the lobster tells more forcibly than 

 words or figures can how closely it is in conformity with the law just enunciated. If 

 a curve is constructed in accordance with the latter, we obtain, as in cut 1, the curve 

 aa, which is the wing of a parabola. Neglecting for the present all data in table 15 

 but those corresponding to the arithmetical series of lengths, 8, 10, 12, 14, 16 inches, we 

 obtain the curve of fecundity represented by the dotted line bb, cut 1. This curve is 

 parabolic and follows the curve aa with remarkable uuiformity up to the region of the 

 fourth term, where the ratio of production is distinctly lessened. This becomes still 

 more marked in the fifth and sixth terms. 



In cut 2 the details of the curve bb are given, including all the data of the table. 

 We see in the line bb 1 the same remarkable conformity to the parabolic curve required 

 by the law. Beyond the fourth term (length 14 inches) the irregularities in the curve 

 become greatest, owing to the small number of individuals represented. 



I believe the law above formulated expresses the propagative powers of the lobster 

 during the height of its sexual activity, although it must not be supposed that the 

 latter conforms uniformly to any arithmetical standard. 



Length of 



im 



19 

 18 

 17 

 16 

 15 

 Lb 

 13 

 12 



mat in 



inches 













b' 





l 















\ 





; 



















- 

















, f 



1 













_...--- 



..---"" 





\ 









r . --"' 



,.-—''' 















** 













; 





_/ r "" 

















/, 

 J 

















10 

 9 

 8, 





















J_ 



















~i i i i VTi i i 



1 1 1 1 1 1 1 1 1 



i 



1 1 1 1 1 1 1 1 1 



i ■ ii 



1 1 1 1 



iii 



in 



1 1 



O I \ lOOOO 20000 3O000 40000 50000 60O0O 7OO00 8000 O Eggs 

 b' a 



Cut 2.— Curve of fecundity of the lobster. 



4 smaller divisions on ordinate correspond to 1 inch in length of lobster. 1 smaller division on abscissa represents 

 1.000 eggs. 



aa\ curve deduced from law of production as theoretically stated. 



66', curve of fecundity deduced from all the data contained in table 15, or from number of eggs produced by 4 645 

 lobsters. ' 



After the lobster has reached a certain age, determined by its early or late sexual 

 maturity, its reproductive energy tends to decline, as is the case with the higher 

 animals, and the ratio of increase, maintained at an earlier period, begins to fall. 

 Whether the highest point of production is ever reached at 14 or 1G inches it is 



