No. 469] 



DOUBLE HENS' EGGS 



23 



have in all cases thus far carefully inquirc(l into piDvcd to Ix- mere 

 clots of albumen or other like materials Laiidoi-. "'.M . it is well 

 known that distomes and threadworms do soinetimes occur iui- 

 bedded in egg shells (Landois, 78; Collin, '94). One of these 

 might well form a nucleus around which albumen could be depos- 

 ited. 



But it must also be kept in mind that the ovary and the oviduct 

 are not such independent organs as perhaps has been implied. 

 Davaine ('01, p. 250) states that Claude Bernard opened a hen 

 that had (lied after laving numerous small yolkless eggs an<l found 

 the infnn<lil)ulnin closr.l and the bo<ly-cavi(y full of volks. It i> 



some indiilct way excite the production of all)umcn in tUv ovl.iu. t, 

 and it is my opinion that many yolkless eggs such as tliat dc-crilicd 

 in this paper, are formed in this way rather than tliai tluy oikc 

 possessed yolks and through some accident lost tlicni. Such 

 questions, however, are subjects for experimental investigation 

 rather than for speculation. 



BIBLIOGRAPHY 



Barnes, R. 



'63. Description of a Specimen of an Ovum in Ovo. Trans. Obstet- 

 rical Soc. London, vol. 4, pp. 87-89, pi. 3. 



'85. Ovum in Ovo: Abnormal Hen's Egg. British Med. Jour., 1885, 

 vol. 2, p. 759. 

 Bartels, M. 



'95. Huhner Ei mit zwei Dottcni. ^>it:iuHis-Ii>r. C/V.sW/.sr//. nnturj- 

 Freunde Berlin, 3 ahvfr. im).-). No. 7. \ 14r>. 

 Bauer, R. W. 



•98. Ueber das l)opj>elei enics Haushuhnof;. liiol. Gentralhi, Bd 

 18, No. 8, p. 304. 

 Chobaut, a. 



'97. Un CEuf de poule monstrueux. La Fcuille d. jeunes Nalural- 

 istes, ser. 3, ann. 27, no. 324, p. 215. 



