the CulGration of Egga. 583 



being ignored. Tlie rat continued to ignore tliem, and I 

 finally removed them. 

 Apparent preference : 



1. Sitagra ocularia. 



2. Amhlyospiza albifrons and Macronyx croceus. 

 Expt. 8. Evening, 8 p.m. — No food since the afternoon 



experiment ; accepted, and readily ate a fresh ego- of A. albi- 

 frons, refused the hard-set egg of M. croceus, and continued 

 to ignore it persistently for perhaps fifteen minutes, but at 

 once accepted and ate an egg of A. albifrons which I now 

 added to that of the Macronyx. I next added to it two 

 C. ardens eggs — one fresh, the other hard-set, and each (as 

 always) opened. 



The rat selected the hard-set Whydah egg and ate it, and 

 I added an. egg each of Prinia mystacea, C. semitorques 

 (unspotted), and (again hai-d-set) of C. ardens. The rat 

 selected the Prinia and ate it. I now had to discontinue 

 the experiment and removed the eggs. 



Apparent preference '. (1) Ainblyospiza albifrons, C. ardens, 

 and Prinia mystacea. (2) Macronyx croceus. The experi- 

 ment was not continued long enough to ascertain whether 

 C. ardens and C. semitorques were really less liked than the 

 Prinia. It may have been merely a selection of one of three 

 species, for all of which he was sufficiently hungry. 



Expt. 9. Feb. 6. — I gave the rat last night, in addition to 

 his porridge, as animal food, a good many small grass- 

 hoppers of the species best liked by my birds. No milk. 

 He had eaten all the grasshoppers when I looked this 

 morning. 



I was busy close by throughout this experiment, and 

 simply ran every three or four minutes to see what was 

 happening. 



The rat at once accepted a nearly fresh Sitagra ocularia 

 egg, and refused yesterday's hard-set egg of Macronyx 

 croceus. I returned later two or three times, and still 

 always finding it uneaten added one o( Amblyospiza albifrons. 

 This was at once eaten. I now left in the Macronyx egg 

 alone, and returning later found that its solider contents 



