TRANSACTIONS OF THE SECTIONS. 69 



the body. After describing the usual phsenomena observable in the egg during the 

 last forty-eight hours of its incubation, as well as at the period of hatching, Dr. Horner 

 stated that the special object of his comnjunication was, to announce the discovery of 

 the true nature of the sound which is heard within the egg during the last two days 

 of incubation ; and also to show what is the exact mode by which the chick breaks 

 the shell. 



The opinion so universally held, not only by amateurs and breeders of poultry, but 

 also by natui'alists and physiologists, that the tapping, or more correctly speaking, 

 crackling sound, heard in the egg on the twentieth and twenty-first days of incuba- 

 tion, were caused by the efforts of the chick to break the shell, he proved to be 

 erroneous, by the following experiments : — first, by breaking a hole in the large end 

 of the egg, when the bill of the chick was seen to be quite stationary, and never 

 coming in contact with the shell, though the sound referred to continued before; 

 secondly, that the sound was heard in other instances before the bill had emerged 

 from the folds of the membrane which envelopes the chick, and consequently, there- 

 fore, could not be then used to break the shell ; and thirdly, by enlarging the aper- 

 ture in the shell first made by the chick so as to isolate the bill, and prevent the pos- 

 sibility of its coming in contact with the shell, when still the same sound continued 

 t» be produced as before, thus proving that the sound heard within the egg was not, 

 and could not be produced by the bill of the chick breaking the shell. 



On examining a recently-hatched chick, by placing the ear and also the stethoscope 

 on its breast and sides, a precisely similar sound was identified as had been heard 

 within the egg. Thus, observed the author, )ny inquiry was complete, viz. that the 

 sound heard within the egg during the last two days of incubation is not caused by the 

 tapping, or by any other mode of contact of the chick's bill with the shell, but that it is 

 truly respiratory, and produced by the transmission of the air through the lungs ; in 

 other words, that it is nothing more than the natural respiratory sound of the chick. 

 Such explanation receives also collateral testimony from the discovery of physiologists 

 that air first enters the lungs of the chick about the end of the nineteenth day, viz. 

 at the very period at which this sound, truly respiratory, first begins to be heard; — 

 and yet more, the author ascertained that the frequency of the respiratory act 

 accorded with the repetition of the sound within the egg. The action of the heart ia 

 a newly-hatched chicken, he observed, was so rapid, that it could not be counted; 

 whilst its impulse and sound were discerned with difficulty. 



The opinion that the shell is broken by a cutting, or scraping motion of the bill, 

 through the agency of the pointed horny scale at its end, was shown to be fallacious, 

 as the membrane which lines the shell is in the first instance left entire, while the 

 shell itself without has been chipped or broken off. The author then observed that 

 the shell is really broken, bit by bit, and with apparent ease, by a healthy chick ; and 

 generally by a single smart blow only, though in some instances the blow is imme- 

 diately repeated, or double ; that each strike of the bill is made with considerable 

 power impinging with force against the shell, as is not only seen, but also felt and 

 heard, by placing the ear against the part when broken ; that when the period of 

 hatching approaches, the chick, which previously had occupied but two-thirds 

 of the egg, now raises itself in the shell by a hustling struggling motion; and by 

 thus unpacking, as it were, of itself, acquires more liberty for its efforts of liberation 

 from the egg. He explained that the reason why the shell is always broken by the 

 chick from left to right, is, because, the chick is so packed in the shell that its head 

 always reclines under the left wing, and on the leftside of its body, so that it can only 

 work and turn with facility towards that side. 



Notice of Jelly Fishes. By Dr. Lankester, F.R.S. 

 The observation was made on the coast of SuflFolk, between the rivers Orwell and 

 Deben, on the 5th, 6th, and 7th of August last. Their numbers were so great as 

 seriously to interfere with fishing operations, and every receding tide left the shore in 

 many places covered with them. The most common species was the yiurelia aurita, 

 next to this Cyanea capillafa. A few individuals of Rhizostoma Pulmo were also 

 taken. Noctiluca miliaris was so abundant, that a hand-net was soon filled on carry, 

 ing it over the surface of the water. At night the water was brilliantly phospho- 

 rescent. 



