THE AMERICAN LOBSTER. 



45 



a series of similar drawings of embryos developing under normal conditions from 

 summer eggs. 



The eye pigment furnishes the most convenient scale for the measurement of the 

 rate of development of the embryo as a whole, since it appears early, is clearly dehued, 

 and since the development of the eye is correlated with that of the other organs of the 

 body. Where the ocular pigment forms a thin crescent in eggs taken in January, 

 the embryo will be found in a stage of development similar to that reached in the 

 summer eggs four weeks after fertilization. In such a case, it is a safe inference that 

 the ova have been laid in the fall. Again, when in May or early June the area of 

 ocular pigment is not greater or is less than that observed in summer eggs by the first 

 of September (cut 36, pi. J), we may be confident that such eggs were extruded later 

 than the previous summer. 



Table 11. — Number of ego-lobsters taken at Woods Hole. {See table il.) 



Females 



Females ! with eggs 



Time. with eggs. ' laid in 



(b) July and 



1 August. 



Females \ 

 with eggs p er „ ent ._ fi 

 laid out of fSffigf? 



season. 

 '(a) 



1893. 



22 



36 

 11 

 12 

 33 

 34 

 20 



17 



24 

 9 

 9 

 26 

 26 

 13 



5 



12 

 2 

 3 



7 

 8 

 7 



22.7 



33J 



18 



25 



21 



23.5 



35 



1894. 













Total 



168 



124 



44 



25.5 





Table 12 shows the stage of development of the eggs of 41 lobsters taken under 

 the conditions described (p. 25) and compared with the normal condition of summer 

 eggs shown in table 18, lobster jSTo. 3 (1) to (20). These comparisons are rendered 

 clearer by a series of drawings (cuts 23-38) made from the eggs of this lobster. 



Table 12. — Stage of development of eggs laid in fall and winter at Woods Hole. 







Length 











Length 





No. 



Date. 



in 



Stage of development. 



No. 



Date. 



m 



Stage of development. 







inches. 













inches. 







1893. 







1894. 







1 



Dec. 20 



10i 



No eyo pigment. Like stage 3 



22 



Mar. 



15 



9* 



Like 3 (11), table 18. 









(7), table 18. 



23 



Apr. 



16 



10 



Little earlier than 3 (10) , table 18. 



2 



Dec. 23 



9J 



Forked telson overlaps brain. 



24 



Apr. 



17 



10 



Like 3 (9), table 18. 









Like preceding. 



25 



Apr. 



17 



10 



Little earlier than 3 (10), table 18. 



3 



Dec. 25 



8 



Like 3 (11), table 18. 



26 



Apr. 



18 



11 



Little earlier than 3 (9), table 18. 



4 



Dec. 26 



10i 



Like 3 (7), table 18. 



27 



Apr. 



19 



81 



Like 3 (91, table 18. 







Dec. 27 



8 



Trifle later than 3 (9), table 18. 



28 



Apr. 



20 



10§ 



Like 3 (10), table 18. 





1894. 







29 



Apr. 



21 



9 



Little earlier than 3 (9), table 18. 



6 



Jan. 1 



IU 



Like 3 (9), table 18. 



30 



May 



1 



lOi 



Little earlier than 3 (10), table 18. 



i 



Jan. 2 



9i 



Like 3 (10), table 18. 



31 



May 



1 



7J 



Like 3 (10), table 18. 



8 



Jan. 3 



m 



Like 3 (9), table 18. 



32 



May 



3 



10J 



Little earlier than 3 (9), table 18. 



9 



Jan. 3 



9* 



Like 3 (11), table 18. 



33 



May 



8 



9J 



Like 3 (9), table 18. 



10 



Jan. 4 



9 



Eye pigment just visible. 



34 



May 



9 



10 



Like 3 (9), table 18. 



11 



Jan. 9 



10 



Like 3 (6), table 18. 



35 



May 



10 



10 



Little later than 3 (9), table 18. 



12 Jan. 11 



10J 



Like 3 (10), table 18. 



36 



May 



11 



7 



Little later than 3 (9), table 18. 



13 Jan. 12 



10 



Like 3 (10), table 18. 



37 



Mas- 



12 



9 



Little earlier than 3 (9), table 18. 



14 I Jan. 13 



10 



Like 3 (9), table 18. 



38 



June 



7 



9 



Like 3 (11), table 18. 



15 



Jan. 20 



9 



Like 3 (10), table 18. 



39 



June 



i 



11 



Like 3 (11), table 18. 



16 



Jan. 27 



10 



Like 3 (10), table 18. 



111 



June 



9 



8} 



Like 3 (11), table 18. 



17 



Jan. 31 



10 



Like 3 (9), table 18. 



41 



June 



8 



11 



Little earlier than (11), table 18. 



18 



Feb. 19 



94 



Like 3 (11), table 18. 



42 



June 



11 



10J 



Like 3 (11), table 18. 



19 



Feb. 5 



9 



Like 3 (9), table 18. 



43 



Juue 



12 



10 



Like 3 (11), table 18. 



20 



Mar. 10 



10J 



Like 3 (11), table 18. 



44 



June 



14 



9 J 



Like 3 (11). table 18. 



21 



Mar. 13 



10i 



Like 3 (11), table 18. 













