848 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



ONTOGENETIC AlIOMETRONS INFLUENCED BY GIANDUIAR INTERNAL 

 SECRETIONS, ENZYMES, AND OTHER ORGANIC CATALYZERS 



The normal hereditary proportions of the skeleton 

 as well as of all parts of the animal body are sustained 

 through causes of two kinds: first, normal heredity, 

 ontogeny, physical environment, and life environ- 



FiGTJRB 754. — Brachj-dactj-ly and dolk-hodactyly 



A, Brachydactyly (short-flngeredness) due to germinal saltation — 

 that is, congenital; after Drinkwater. B, Brachydactyly that is 

 not congenital but developed secondarily after birth through exces- 

 sive internal secretions of the pituitary gland. C, Dolichodactyly 

 (long-flngeredness) [developed after birth, attributed to abnor- 

 mally insufficient secretions of the pituitary gland. B and C 

 after Cashing, 1912.1. 



ment — that is, tetraplasy, the principle 

 fully explained above; second, normal 

 interactions between all parts of the 

 body, probably included in tetraplasy. 

 These normal interactions are in part 

 sustained by the nervous system, in part 

 by the various kinds of physico-chemical 

 catalyzers Icnown as enzymes, internal 

 secretions, including hormones (accel- 

 erators) and chalones (retarders), sum- 

 marized by Osborn (1917.462, pp. 250- 

 251), from the researches of Simpson, 

 Ashner, Gushing, Schafer, Goodale, 

 Lillie, as follows: 



These include many changes of proportion 

 in mammals, which are not Icnown to have 

 a selective survival value. We may instance 

 in man, for example, the long-head form 

 (doUochocephaly) and the broad-head form 

 (brachycephaly) , or the long-fingered form 

 (dolichodactyly) and the short-fingered form 

 (brachydactyly) , which have been interpreted 

 as congenital characters appearing at birth 

 and tending to be transmitted to offspring. 

 Brachydactyly may be transmitted through 

 several generations, but until recently no one 

 has suggested what may be its possible cause. 



It has now been found [Gushing, 1912.1, 

 pp. 253, 256] that both the short-fingered 

 condition and the long-fingered condition 

 may be induced during the lifetime of the 

 individual in a previously healthy and nor- 

 mal pair of hands by a diseased or injured 

 condition of the pituitary body at the base of 

 the brain. If the secretions of the pituitary are abnormally ac- 

 tive (hyperpituitarism) the hand becomes broad and the fin- 

 gers stumpy (fig. 118, B) . If the secretions of the pituitary are 

 abnormally reduced (hypopituitarism) the fingers become taper- 

 ing and slender (fig. 118, C). Thus in a most remarkable man- 

 ner the internal secretions of a very ancient ductless gland. 



attached to the brain and originating in the roof of the mouth 

 in our most remote fishlike ancestors, affect the proportions 

 both of flush and bones in the fingers, as well as the propor- 

 tions of many other parts of the body. 



Whether this is a mere coincidence of a heredity chromatin 

 congenital character with a mere bodily chemical messenger 

 character it would be premature to say. It certainly appears 

 that chemical interactions from the pituitary body are con- 

 nected with the normal and abnormal development of propor- 

 tions in distant parts of the body. 



Allometrons, as shown above, are partly examples 

 of biocharacter velocity. Some of the above phe- 

 nomena of abnormal interaction in the organism may 

 give us an insight into the possible causes of slow or 

 rapid movement, of acceleration or retardation, in 

 the origm of allometrons. These internal secretions 

 may be connected with the fact that one proportion 

 is retarded, as if suffering from inertia, while a con- 

 joining proportion biocharacter is full of life and 

 velocity, accelerated, like the alert soldier in the 

 regiment. Whether or not internal secretions prove 

 to be among the causes of the evolution of proportion, 



Figure 755. — Examples of dwarfing due to removal or abnormal functioning of 

 certain glands 



Harmonic and disharmonic alterations of proportion in mammals due to removal of the thyroid, para- 

 thyroid, pituitary, and other glands. A (rightl, Normal sheep of fourteen months; Oeft) sheep at the 

 same age from which the thyroid and parathyroids were removed at the age of two months: after Suther- 

 land Simpson. B (right). Normal dog of twelve months; (left) a dog of the same age and litter from 

 which the pituitary gland was removed at the age of two months; after Aschner. C, Dwarfed ma- 

 crocephalic pigmies of the hills compared with tall microcephalic plains men of west-centrfil New 

 Guinea; after Rawling. The question arises whether the dwarfing and macrocephaly of the pigmies 

 may not be due to abnormal interactions (internal secretions) of certain glands like the thyroid. 



they are certainly among the causes of normal and 

 abnormal development of proportion. Theoretically 

 it is conceivable, as suggested by Cunningham 

 (1908.1), that since hormones and chalones determine 

 the rate of development of many organs they may 



I 



