176 OTTO GLASER. 



hens. Bartels ('95, p. 143) states that the hen that laid the 

 double egg described by him had often laid such eggs, and 

 Immermann ('99, p. 8) records the case of a hen that laid such 

 an egg about every eight days. Apparently this is as much an 

 organic peculiarity of certain hens as is the production of twins 

 by certain individuals in the human species, and while it may be 

 called abnormal in that it is unusual, it is in no sense indicative 

 of serious organic derangement or disease." 



Despite the fact that the origin of double-yolked eggs can be 

 attributed, as it is by Parker, to an ovarian peculiarity, such as 

 the simultaneous discharge of two yolks from separate follicles, 

 or the rupture of one follicle containing two yolks, there never- 

 theless are two other possibilities. In the first place, an ovum 

 discharged into the infundibulum might fail to be moved down- 

 ward by peristalsis until the ovary had discharged a second time, 

 in which case we might be dealing either with a deficiency of 

 substances normally inducing these movements, or with sub- 

 normal irritability on the part of the oviduct. In the second 

 place, the "organic peculiarity of certain hens" may have an 

 ovarian basis decidedly "indicative of serious organic derange- 

 ment" if not of disease. The ovary which I have studied is 

 certainly pathological although I cannot conclude that the con- 

 ditions found are the only ones that induce double-yolked eggs, 

 or that they always do so. 



Unfortunately the bird on which my data are based died 

 during my absence and the oviduct was not preserved. However 

 the ovary seems to me capable of explaining why she laid ab- 

 normal eggs, although this does not show that the oviduct was 

 normal either in structure or in action. Normality however 

 seems likely, for if there had been peristaltic difficulties it seems 

 reasonable to suppose that occasionally at least an egg abnormal 

 in other respects would have been produced. This is not known 

 to have happened in the five years during which this hen was 

 under fairly constant supervision. 



CLINICAL HISTORY OF THE INDIVIDUAL. 



The bird in question, a white leghorn belonging to Mrs. Wm. 

 Looker, of Ann Arbor, was hatched in the spring of 1906 and lived 



