12.^ 



TAOR SKOGSBERG 



,,Tlie ratios for Brooks's law ronu' out sufficiently clearly, although the total numbers 

 are small, and in spite of the difficulty of separating this species from magna at the lower stages. 



Taking the means as a basis for calculating: 



? 1.07 X 1,48 = 1,58; 1,68 X 1,48 = 2,33. 



0*0,77 X 1,40=1.078: 1,08 x 1,40=1,51: L.W x 1,40 = 2,10" (1,51 x 1,40 = 2,11), 

 (p. 266). 



. Conchoecm rhynchena G. W. MUller. 



Stage 11. 

 Mean 2,47. 



Stiigi' HI. 

 Mean 1,60. 



Mean l.O'i. 



Stage v.! 

 Mean 0,70. 



Length in mm.: 

 Niimber of 2 measured: 



Total specimens measured: 28 ?. 



,,In the females the reaction to a growth-factor is very close: — 0,7 x 1,54 = 1,07; 

 1.04 x 1,54 = 1,60; 1,60 x 1,54 = 2,46. As there are only three males to represent Stages III. 

 and TV., it is useless to discuss their growth-factor." (p. 272). 



Gonchoecia imhricata (G. S. Brady). 



stage II. 



Stage III. 

 Mean 1..'.0 



Stage IV. Sliigc \. 

 Mean 0,96 MeanO.fiC, 



Xnmber of $ measured: 

 I.eneth in mm.: 

 Number of ^ measured: 



3 



2,5 



7 12 

 2,4 j 2.3 



1,4 



5 



1,3 



1.2 



1,1 



11 



1,0 



14 



6 

 0,9 



0.8 



0,7 



1 

 0.6 



Stage II. 

 Mean 2,01 



Stage III. 

 Mean 1.48 



Stage 1\'. 

 Mean 1.0 



Total specimens measured: 65 ? -j- 36 ^. 



.,Now, taking the mean lengths of the females at the different stages: — 0,62 x 1,56 = 

 0,96; 0,96 x 1,56 = 1,497; 1,50 x 1,56 = 2,34 .... The males are much fewer and there- 

 fore respond le.ss accurately: — 1,0 x 1,45 = 1,4; 1,4 x 1,45 = 2,03." (pag. 225). 



Gonchoecia dafhnoides C. Cl.AUS. 



Stage I. 

 Mean 3.08. 



Stage Ul. 

 Mean 1,*2. 



Length in mm. : 

 Number of $ measured : 



Total specimens measured: 112 ?. 



,,In addition to the numerous specimens of Stage I. there was a single female specimen 

 of (apparently) Stage III.; this with the aid of a slide-rule enables one to make an empiric 

 guess at the mean of Stage II. With a growth-factor of 1,6 for females it appears that 1,2 x 

 1,6 = 1,92; 1,92 x 1,6 = 3,07; and we may fairly presume that the mean of Stage II. will 

 be a little more or less than 1,9" (p. 263). 



