142 



REPORT 1860. 



a mouth so large that a needle can easily be introduced into it. If, however, the in- 

 crease of size be simply by imbibition through the skin, these would be of no use. 



Moreover it is very common to see other eggs actually in the oesophagus of the 

 embryos in the act of being swallowed ; or we might almost say that an embryo is 

 seldom seen without an egg in its oesophagus. In Purpura, according to Dr. Car- 

 penter, the yolk is swallowed particle by particle ; in Buccinum, on the contrary, 

 the eo-o-s not having undergone any segmentation, are swallowed whole, and the 

 process of deglutition is therefore probably less rapid and more easily seen. The 

 presence of yolk matter in the oesophagus of Purpura may also be more plausibly 

 ascribed to accident than in Buccinum, where, from the large size of the egg com- 

 pared to that of the embryo, it cannot take place without a considerable tension of 

 the oesophagus, and the swallowing must therefore apparently be a work of some 



M. Milne-Edwards suggests (Ann. des Sc. Nat. 1. c. p. 26) that the so-called eggs 

 are probably only " des spheres vitellines, dout 1' envelope utriculiforme prdsente" 

 im peu plus'de cbnsistance que d' ordinaire, et que, par consequent, l'agregat dont 

 nait le corps de l'embryon est le reaultat du groupement des spheres vitellines d'un 

 seul oeuf et nonle produit de la reunion de plusieurs ceufs primitivement distincts." 



It will be seen, however, from the preceding description, that though M. Milne- 

 Edwards was fully iustified in the scepticism with which he regarded the descrip- 

 tion given by MM. Koren and Danielssen, he was not equally happy in his 

 attempt to explain away the supposed anomaly. 



Fig. 1. Embryo in outline, to show the mouth and digestive cavity. 

 Fig. 2. Young embryo in the act of swallowing an egg. 



On the Influence of Systematized Exercise on the Expansion of the Chest. 

 By Archibald MacLaren. 



Exercise is the most important agent in physical growth and development, inas- 

 much as it qualifies the condition, the action and the influence of all the others. This 

 importance is not always appreciated, because the effects of exercise on any part of 

 the body but the muscular system are imperfectly understood. All exercises may 

 be classed under two heads, Recreative and Educational. The first of these em- 

 braces all our school games, sports and pastimes, — a most valuable list, but quite in- 

 sufficient to produce the perfect development of the body : — 1st, because the parts 

 of the body chosen to execute the movements of the game are those which can 

 do them best, not those which need the exercise most ; 2nd, because it is a distinc- 

 tive feature in the best and most ardently practised of them, that they give a large 

 share of employment to the lower half of the body, and but little (some not at all) 

 to the upper half; and 3rd, the little which they do give is almost monopolized by 

 the right side. The tendency of these exercises is therefore to develope the lower 

 half of the body to the exclusion of the upper. It must always be remembered that 

 while in developing a limb to its full power and perfect conformation, we do that 

 and nothing more ; in developing the trunk of the body, we do that and a great deal 



