68 



BULLETIN OF THE UNITED STATES FISH COMMISSION. 



Table 20. — General condition of the sexual organs, of the external and internal eggs, etc. — Continued. 



No. 



Sex. Length. 



86 : Female 



87 ...do..., 



.do. 



89 i ... do . . 



90 '...do.. 



Date of 

 capture. 



Inches. 

 11 



1890. 

 Aug. 21 



..do . .. 



.do 



91 ...do.... 



92 ...do ! 



99 



100 



..do... 

 .do ... 



..do ... 



...do... 



...do... 

 ...do... 



...do ... 

 ...do ... 



...do .... 

 ...do... 



1891 

 July 22 



...do .... 



Locality. 



Gay Head, 

 rock bot- 

 tom. 



do 



.do 



.do 

 .do 



Woods Hole 



Harbor. 

 do 



July 24 do . 



July 30 do 



July 30 



Aug. 4 



Aug. 5 



.do 



.do. 



Menenisha. 



June 30 Woods Hole 

 Harbor. 



11J July 18 j Menemsha. 



Condition of sexual 

 organs. 



Ovary cream color . 



Ovary liglit green, 

 flecked with yellow 

 (degenerating eggs) 

 and white (young 

 eggs). 



Ovary whitish , flecked 

 with yellow spots, 

 and dark green un- 

 extruded eggs. 



do 



Ovary same as in No. 87. 



Ovary white, 15mm. in 

 diameter. 



Ovary whitish, with 

 tinge of pink, 3 mm. 

 in diameter. 



Ovary white, about 

 3mm. in diameter. 



Ovaries nearly ripe; 

 seminal receptacle 

 charged with sperm. 



Light green. Ova light 

 yellowish green. No 

 sperm in seminal re- 

 ceptacle. 



Ovary nearly ripe. Fe- 

 male impregnated. 



Ovary light pea green. 



Female impregnated. 

 Ovary white; length If 



in. ; diameter J* in. 



Condition of swim- 

 merets. 



Clean . 



External eggs 

 about six weeks 

 old, extruded 

 about July 10. 



External eggs in 

 egg - n a u p 1 i u s 

 stage, laid about 

 August 6. 



do 



Clean 



Remarks. 



Immature. 



Very hard shell. See 

 drawing of ovary and 

 ova, figs. 137 and 135, 

 plate 38. 



Soft shell. 



External eggs in 

 late segmenta- 

 tion. 



Shell fairly hard. 

 Ho. 



Hard shell. 



Do. 



Do. 



Hard shell. For sec- 

 tion of ovary, see tig. 

 140. 



Shell hard; to molt 

 soon; eggs hatched 

 this season. See 

 drawing of ovary and 

 ovum, figs. 138 and 

 133, pi. 38. 



Hard shell. See draw- 

 ing of ovary, fig. 132, 

 pi. 38. 



Eggs laid about. July 25. 



These results, with those giveu in table 15, show very clearly that on the coast of 

 Massachusetts female lobsters become sexually mature and produce eggs for the first 

 time when they have attained the length of from 8 to 12 inches. Very few lobsters 

 under 9 inches in length have external eggs, while only few have attained the length 

 of 10.J inches without having them. The limits of 9 and 10 inches, which have been 

 variously adopted, are therefore too small, and should be increased if the lobster is to 

 receive the benefit which is intended by this form of legislation. It is clearly illogical 

 to protect the very small lobster and not to extend protection to the lobster which is 

 about to spawn, in view of the natural increase of the species, since the latter has the 

 greater chance of survival. It is highly probable that the majority of female lobsters 

 10i inches long are sexually mature. It is possible that the limit is sometimes extended 

 at both extremes and that very rarely a lobster produces eggs before it is 8 or even 7£ 

 inches long or fails to produce them until it is over 12 inches in length. Out of over a 

 thousand egg-bearing lobsters which have been examined at the Woods Hole station 

 during the past four years there have been found only 20 lobsters measuring from 8 

 to 8f inches, or less than 2 per cent of the total number with external eggs. (For 

 statistics of the majority of these, see table 15.) The hundred lobsters, the dissec- 

 tions of which are tabulated above, were not, however, taken at haphazard, but were 

 selected in many cases to illustrate the development of the ovary and its growth 

 between two successive sexual periods. 



