So 



The study of oological abnormalism is one to which I have 

 devoted much time, using as my subjects such specimens as 

 came under my personal observation during systematic field 

 work and those secured through correspondence. The collec- 

 tion thus brought together numbers one hundred and ten sets, 

 aggregating four hundred and thirty-three eggs, of which two 

 hundred and three are decidedly abnormal; some only in 

 one particular characteristic while others show a combination 

 of imperfections. Ninety-seven are abnormally colored, some 

 possess a strangely tinted ground or are purely albino; many 

 possessing a normal ground color are wholly or nearly immacu- 

 late, or are oddly marked with a superfluous abundance of color 

 pigments. One hundred and twenty-two are defective in size, 

 a large percentage of which are runts of variable patterns. 

 Quite a number of mor.strocities are present, and others which 

 have one of their diameters normal are decidedly abnormal in 

 the other. Departure from normal shape is noticeable in eighty- 

 two of the specimens, many of which are of a spherical appear- 

 ance but extremely long narrow specimens are numerous as 

 well as abnormal pyriform types. 



Just why a bird should finish off and lay a small malformed 

 runt or an extremely large egg has never been fully understood 

 by me, and equally perplexing is the unnatural absence of color 

 pigment from some specimens or the abnormal presence of it 

 on others. When I consulted my library, only meager statements 

 were found; and these were applied in a general way, leaving 

 the cause imperfectly defined; and while some explanations 

 seemed plausible, their application was not consistent in all in- 

 stances. Owing to these facts I have compiled the present pa- 

 per from the evidence at hand, based on the specimens and data 

 in my possession, giving such details as the facts in the various 

 cases indicate. 



Coloration.— Of the ninety-seven eggs abnormally color- 

 ed, fifty-eight are abnormal in coloration only, being in all other 

 respects typical specimens. It is an interesting fact that the 

 monstrocities are normally colored as well as a large percent- 



