508 Erste Sitzung der fünften und zehnten Sektion. 



weight between the limits of 76.0 and 8434.0 grams, and in length 

 between 33.0 and 135.0 centimeters. About 35 measurements 

 were made of each specimen, including various external charac- 

 ters such as dimensions, proportions, fin areas, et cetera; and 

 also the weights of certain internal parts-brain, ventricle of the 

 heart, pancreas, spieen, liver, rectal gland, ovary, testes. 



Omitting all details as being out of place here, the general 

 results are susceptible of very brief resume. As the fish increases 

 in total weight the brain increases also, but at a slower rate than 

 the whole fish, so that while at birth the brain constitutes 1.2% 

 of the total weight, in fish of about 5 years (probably) of age, 

 weighing some 2500 grams, the brain constitutes only 0.2% of 

 the total, and in the largest specimens of 5000 to 8000 grams 

 this falls to only 0.1%. That is, among the largest individuals 

 the brain is relatively only one-twelfth as large as at birth (dia- 

 gram). Similarly (diagrams) the ventricles of the larger speci- 

 mens are proportionately only two-thirds as heavy as at birth : 

 the rectal gland only one-half as large: the pancreas only one- 

 half as large: the spieen only one-fourth as large. Not only is 

 there this considerable diminution in the relative size of these 

 parts, but further each organ grows in its own characteristic way 

 — each has an individual form of growth curve (diagrams). The 

 liver is specialized as a fat-storing organ and has a growth-curve 

 decidedly unlike any of the other organs and the ovaries and 

 testes have still other pronouncedly different curves. In n o 

 case does the rate of growth of the organism 

 as a whole give an indication of the rate of 

 growth of any of these parts. 



Another interesting relation is that of the area of the fins 

 used in locomotion — the caudal and pectoral fins. Among the 

 larger specimens the total area of these fins is, relative to the 

 whole mass of the fish, but one-fourth of what it is in the fish at 

 birth. The most important organs of locomotion may be thought 

 to be the muscles of the tail region and I have some data that 

 give a fair indication of the rate of growth of these as compared 

 with the weight of the whole fish. The volume of the tail from 

 its base to the beginning of the caudal fin includes these muscles 

 and little eise save the axial skeleton and associated structures. 

 This is found to show a steady decrease proportionally so that 

 in the larger specimens it is only about three-fourths what it is 

 in the smaller individuals. 



It is clear then that descriptions of the growth of these fish 

 by statements regarding changes in total weight would be entirely 

 inadequate and really without particular significance. This orga- 

 nism does not grow as a whole; its organs, or perhaps tissues, 

 grow as more or less separate units. It has been suggested that 

 in man at least, stature is a better index of growth than is total 



