n^ PHYSIOLOGICAL 



be only a matter of a few generations to obtain something 

 so closely approaching fixity as to be of permanent practical 

 value. Such work could best be carried out at a joint Institute 

 for Animal Breeding and Animal Nutrition, where this and 

 many kindred problems could be effectively studied, and we 

 know of no way by which anyone who has the will and the 

 means to benefit our national live-stock industry could do so 

 with a better assurance of success than by providing an endow- 

 ment for such a scheme. 



Before we leave the subject of marbling there is another point 

 of both physiological and practical interest which is worthy of 

 our attention. The analyses of the ilio-spinalis muscle in some- 

 thing over 80 beasts have consistently shown that the amount 

 of intermuscular fat diminishes in passing backwards from the 

 anterior ribs to the posterior ones, and that the proportion 

 present in the wing rib and first cut of loin is invariably con- 

 siderably smaller than in the middle rib. In view of the 

 importance attached to marbled meat this result might seem 

 surprising, since the loin and prime ribs are universally regarded 

 as the best joints in the carcase. But it has been pointed out 

 above that the fat occurring in marbled meat is not deposited 

 within the fibres but in the connective tissue which surrounds 

 and binds together the bundles. Moreover, the meat which 

 is near or in immediate anatomical connexion with skeletal 

 structures contains more connective tissue than that which is 

 further away. This connective 'tissue when well developed is 

 one of the factors (but only one of them) in making meat tough. 

 Here at once we have the explanation as to why the joints cut 

 from the posterior ribs and loin are apt to be more tender, and 

 ,at the same time less marbled than the joints taken from the 

 anterior ribs or elsewhere, since the muscles composing the 

 meat of the hind ribs and loin for the most part have their 

 insertions and attachments at the fore end and hind end of 

 the animal. But it must be clearly understood that although 

 marbling appears to depend upon the existence of connective 

 tissue, the converse of this does not follow, for, as we have seen 

 above, the transformation of fibrous or elastic into adipose 

 tissue is dependent upon "condition," besides being probably 



