06 



CANARIES, HYBRIDS, AND BRITISH BIRDS 



ixmltry, of wliicli Mr. Wriolit I feats, than 

 the coos of those wliich build in a bush, 

 or which breed in captivity in caocs. In 

 lact, we have very little faith in the idea 

 liiat coos incubated by birds Ihat build 

 some distance from the ground are affected 

 by storms, and after years of close study 

 of the subject wc have not found any 

 authentic record of hurt result ino. other 

 than that of the inirely imaoiiiarv kind, 

 of which we have heard of many. 



" Win never tlic coo- js aoain subjected 

 to a heat analooous to that of the hen's 

 l)i>dy, the process of development is re- 

 sumed, if the interval has not been too 

 loiio. There can obviously be no dclinitc 

 limits to such an interval." 



iMuch depends upon the strenoth of the 

 germ: it is onl\- natural to ])resumc that a 

 weakly germ would perish sooner than one 

 which was strong and healthy. In cases 

 of hens refusing to sit wc have kept eggs 

 a week, lying on bran in the dark, turning 

 them daily, and have had them sueccssfully 

 hatched, and the young reared. We have, 

 however, also been unsuccessful with fertile 

 eggs kept a similar time, the weaker germ 

 having doubtless perished. There might 

 be other causes for the failure, but it is 

 only reasonable to say there is a dilTercnce 

 in the strength of the germ, just as there 

 is a dilTereiice in the strength of birds. 

 though we have again and again seen 

 l)uny youngsters grow into line robust 

 birds. ()b\iously it is well to get all eggs 

 under the hens, .■md on their \\;iy to incu- 

 bation as soon as ]ie)ssible after the full 

 cluleli is l:iid. 



It is needless to describe in detail the 

 development of the chick when steadv 



in<-nb,il ion has been com- 

 Development i • .. i 



<■ .1. r-i. I. meneed. A lew hours en- 

 of the ChicK. 



large Ihe central ])elluci(l 

 s|)ot. which becomes o\al. with a furrow 

 down the centre, and blood-vessels ap|)ear 

 round it : Ihen begins to (levelo|) a double 

 membrane ealk'd the (inniidii. which at a 

 later |)eriod entirely encloses Ihe eiiibrx'o. 

 along with \\h;il is c.-dled Ihe anmiolic 

 lluid. 15y I he: second or I bird day the tiny 

 embrvo enelosetl in the anmion can be 



clearly seen, as in the accompanying illus- 

 tration, surrounded by a |)ateh upon the 

 surface of the yolk which is covered bv 



CUICK ON SKCOND OR TIURO DAY (Miienifml). 



line blood-vessels. The eyes can also be 

 seen with a magnifying glass, as dark spots, 

 and even the jiulsation of the heart. At 

 or soon after the thii'd (la\' another growth, 

 called the ulhiiiltiis. begins to push out 

 from the digestive canal of the embryo 

 between the two coats of the amnion, anil 



FIFTH nA^ : Hi AIlaiKciis (Mal^nifu-A). 



at ;i later ])criod also encloses the embryo. 

 J{\ the fifth or sixth day Ihe allantois can 

 be eleai'K- seen as a bag or sac ])rotruding 

 from the na\cl. indc])endenl of Ihe yolk- 

 sac {sic illustration). I5y this time I'luli- 

 mcnts nl the wings and legs can be clearly 

 seen as buds oi- small clubs standing out 

 from the surface of the body, which has 

 grown a great deal, 'i'lie network of 

 l)lood-\-essels has also extended, and the 

 yolk-sac is larger and more delined. This 

 and the devclo|)ing allantois. at about the 

 se\ciitli (la\. ale more clearly shown in 

 the next illiisl rat ion. 



"The allantois is. liowcNir. Ilallened 

 and spreatl out in lealitx bttwien the 



