37 



nothing: now that my general suspicion of egg is 

 changed into something more definite the case is 

 altered, and no great effort of imagination is required 

 in this case as in many others to fix the blame where 

 it was due. 



As I shall have to treat of egg food in connection 

 with yet another disease affecting cage-birds, and as 

 in the next chapter we must proceed to the discussion 

 of the actual pathological aspects of septicaemia, the 

 above remarks must now suffice on the subject of this 

 pernicious but widely recommended article of diet. 

 Indeed to the thoughtful reader it is hardly necessary 

 for me to say more ; he can find much to arrest his 

 attention in almost every article or letter dealing with 

 the experiences of bird keepers, and bj^ the light of 

 what has been said in these pages can easily put his 

 finger on the true reason of many recorded puzzles 

 and disappointments. In particular I would direct 

 his attention to the numerous cases where rare birds 

 have been persuaded to breed but have only half 

 reared the j^oung, owing ''solely,'' as the chagrined 

 owners always think, " to the difficulty of providing 

 sufficient live insects." 



To recur to the question of comparative immuni- 

 ties, it will by this time have been gathered that as 

 regards this there is not only a great difference 

 between domesticated and wild birds, but also that 

 amongst the latter there is in this respect a con- 

 siderable divergence between the different species 

 and genera. Just as the ordinary "seedeaters" are 

 more susceptible than those which are arbitrarily 

 differentiated under the title of " insectivora," so in 

 both .sections we meet with decided gradations. 

 Take for instance the Yellow Ammer and the House 

 Sparrow, both of them mixed feeders. Klein found 

 in his experiments that when he inoculated the 



* This question will be dealt with iti a chapter on Digestion and Bird Foods 



