the Coloration of Eggs. 591 



Conclusions from Experiments on the Rat. 



The rat's preferences in eggs were more marked than the 

 lemur's, the unwelcome eggs being in some cases allowed to 

 lie neglected for many hours together, even when the animal 

 was more or less hungry ; and, again unlike the lemur, the 

 rat did not require to be fed nearly to repletion before he 

 would begin to discriminate. A marked exception to this 

 rule occurred on Feb. 5th, when the animal lapsed into 

 complete indiscriminateness. An insufficiency of animal food 

 during the preceding twenty-four hours, in combination with 

 the bitterly cold day, suggested itself to me as an explana- 

 tion, and I tested this in my subsequent dieting of the rat, 

 but it may not be the correct one. At any rate, he usually- 

 discriminated and was consistent, and it is possible to set 

 forth approximately the preferences shown in the form of 

 the following table — not that the material used in these 

 experiments was sufficient to justify us in supposing that 

 their results necessarily represent what would have been the 

 rat's final verdict on all the species used. Still, the lemur's 

 general confirmation of the rat's preferences seems to show 

 that — at any rate, in the main — they represent the impression 

 the eggs would make on an egg-eating animal, and a second 

 rat, on which, owing to its extreme wildness and the limited 

 supply of eggs, I did not continue to experiment, showed 

 exactly the same initial eagerness for the eggs of Weavers 

 and the same dislike for an egg of P. layardi : — 



Estnlda astrild, f 1. Sitagra omilana. 



Cisticola natalensis, 2. Amblyospiza albifrons, T Coliuspasser ardens. 

 „ subrujicapiUa, J 3. Hyphantornis jamesoni J 3. -i Cisticola semi- 



4. Crateropus kirki, I torques. 

 Tel. senegalus, J 4. 



5. Pycnonotus layardi, Dryoscopus 

 Colius striatus. r guttatus, 



6. Macronyx croceus, Serinus Centropus. 

 icterus, Chalcopelia afra. J 



Prinia mystacea. 

 Turtur capicola. J, 



On one occasion only, I think, Amblyospiza was eaten in 

 preference to Sitagra. 



