320 On the Amyloid Substance in the Animal Economy. [June 16, 



to vary a good deal in amount. But this much may be asserted positively, 

 that for some time before birth it has much diminished in quantity in this 

 tissue, although always existing in it in notable amount up to and after 

 birth. After repeated examination of various embryos, I believe I may state 

 that the following Table, made from examination of the voluntary muscular 

 tissue of foetal lambs, correctly represents the average quantity of animal 

 dextrine found in this tissue at various periods of its growth* : — 



Size and condition of the embryo. 



Quantity 

 of fresh 

 muscular 



tissue 

 examined. 



Weight of 

 the foregoing 



when 

 thoroughly 



dried. 



1st. 



2nd. 



3rd. 



4th. 



5th. 



6th. 



4 inches long 



7 inches long ; hair on lip 



10 inches long; hair on head 

 very fine 



15 inches long ; covered with 

 delicate hair 



16| inches long ; well covered 

 with fine hair . . , 



Nearly 20 inches long, and al- 

 most about to be born 



30 grains. 

 60 grains. 



60 grains. 



60 grains. 



60 grains. 



60 grains. 



1"7 grain. 



5- 5 grains. 



6- 2 grains. 

 7*5 grains. 

 7*8 grains. 

 9*5 grains. 



It appears therefore that, although it exists in a less proportion than at 

 an earlier period, there is in muscular tissue at the period of birth a consi- 

 derable quantity of amyloid substance ; and this does not disappear alto- 

 gether for some time in lambs, occasionally not for some weeks after birth. 

 The tissue of voluntary muscle cannot be considered to have attained matu- 

 rity at the time of birth ; it has as yet hardly been called upon to exercise 

 its functions. There is, however, a muscular organ the tissue of which 

 commences, of necessity, the active exercise of its functions at an earlier 

 period than that of voluntary muscle. The muscular structure of the 

 heart, so far as its functions and activity are concerned, attains maturity 



Size and condition of the embryo. 



Weight of 

 the muscular 

 tissue of the 

 heart 



examined. 



Amount of 



amyloid 

 substance in 

 foregoing. 



1st. 



2nd. 



3rd. 



4th. 



20 inches long, just before birth 



20 grains. 

 20 grains. 

 20 grains, 



20 grains, | 



1*52 grain. 

 1*60 grain. 

 1-76 grain, 

 A trace too 

 small to weigh. 



* It was stated in my former communication that 3*5' grains of amyloid substance 

 was obtained from 60 grains of muscular tissue of a fatal calf; but this was not quite 

 pure, the investigation not being made with so much care as in the present instance. . 



