46 E. W. SEXTON AND M. B. WING. 
laid but thrown off, then the male died and was eaten. A Pure Black 
male was put in, mated with one of the females, but ate it after mating. 
By September 26 only the two females B and C were left. The “ all- 
white ” male from the Pure Red Stock with unpigmented perfectly formed 
eyes (Fig. 8) was put with them and mated at once with female B (Figs. 
9 and 10), eggs were laid, and 5 young were extruded, on October 16, all 
with normal eyes, 2 Black and 3 Red. This result proved beyond doubt 
that female B was a true Hybrid and the male a true Recessive. 
The second female, C, was left with the same male, but as no mating 
had taken place by October 28, a Red male was added, mated, and the 
eggs were laid on November 4. 
The figures given of the eyes and eye-colours are all taken from living 
animals, for the colours alter so rapidly after death, that notes made on 
the colour in dead or preserved specimens are not of the slightest value. 
For instance, the white pigment disappears within an hour or two of 
death, and the red also fades out completely, though much more gradually. 
GENERAL NOTES. 
Breeding different generations together —Eight experiments were made 
with males of the F, generation and females of the F,: one with R. x H.; 
two with H.x R.; two with H. x H.; and three with H. P. In the first, 
the male was rather small, mated three times, and carried the female for 
7, 6, and 6 days respectively with no results; female disappeared. In 2nd 
Kixp. the female was eaten; 3rd Exp., one brood of 26 young was hatched, 
11 Black and 15 Red, the male died; 4th Exp., one brood of 6 young ; 
5th Exp., eggs were laid, not hatched, male died; 6th Exp., same male as 
in the second experiment, one brood of 5 young, male died; 7th Exp., 
female laid eggs but died before they hatched; 8th Exp., four broods of 
36, 17, 30, 30; male eaten. The results are not satisfactory, probably 
because of the difference in size. The females were large, and the males 
had only just reached maturity. When the animals are about the same 
size there is nothing to distinguish their matings from those of animals 
of the same generation. 
Fertiliiy.—A great variation in fertility has been noticed, not only in 
individuals, but often in all the members of any one brood. 
Some instances may be given in illustration from broods of the F, 
generation of the Recessives. As an example of infertility Brood 1 of 
Exp. 9, p. 27, may be taken. Ten voung were hatched, and most of 
them reached maturity, but after six months’ breeding they all perished 
without leaving a single descendant. Brood after brood of eggs were 
laid, but not a single young one was hatched. 
