i68 Viewpoints in the Study of Grozvth [Jan. 



growth; defects may occur iinrevealed in the curves or gross mani- 

 festations, yet involve the finer structures of the organism which 

 are hidden to the naked eye. 



The use of the term growth with its several connotations has 

 not infrequently led to a confusion with phenomena which are in 

 reahty distinct therefrom. The distinctions are freqiiently subtle, 

 yet none the less important. Thus the pathologist employs the 

 terms hypertrophy and hyperplasia, the latter type of enlargement 

 being the one dependent on the formation of new cells. In mam- 

 mals, for example, there is no hyperplasic growth in the nervous 

 elements after birth. Other tissiies, such as the connective and 

 epithehal varieties, show abundant hyperplasia. 



The increase in size or weight that is observed in adult life has 

 also been correlated with growth. The processes are presumably 

 distinct. This addition to the organism or deposition of new mate- 

 rial therein — the " Körperansatz " or " Mast " of the Germans — 

 plays an important part in the "finishing" of cattle for the market. 

 The "Ansatz" may be of a more permanent type such as charac- 

 terizes the deposition of fat, glycogen or even protein in the cells; 

 or it may be decidedly " unstable," representing water largely rather 

 than food elements assimilated in proper proportions. This latter 

 aspect of the storage depots in the body, in which water is present 

 in exaggerated amounts, is not infrequently met with in pathology. 

 True "Ansatz" must be distinguished, furthermore, from repair 

 (reparation, realimentation, reconvalescence, recuperation, recov- 

 ery) which takes place when by inanition, disease, or malnutrition, 

 or all combined, growth has been checked in the adolescent or body 

 weight lost in the adult. The increase in size attending realimen- 

 tation has not infrequently been confused with true growth. They 

 may be, and presumably are, distinct processes. In the one case 

 depleted structures are restored, in part by mere deposition and 

 restitution of the storage depots ; in growth, novel changes are ini- 

 tiated in addition. There are indications available that the chem- 

 ical and metabolic processes of repair are by no means identical with 

 those of growth. 



Growth and regeneration undoubtedly have much in common; 

 yet they deserve individual treatment. Quoting Morgan, "the 

 word ' regeneration ' has come to mean, in general usage, not onl}'' 



