266 POSTNATAL GROWTH OF HEART, KIDNEYS, LIVER, AND SPLEEN. 



long bones alternate in growth. The growth of the individual teeth alternates from mandi- 

 ble to maxilla or the reverse, and from one tooth to another at some distance from it. The 

 head and thorax alternate in growth, the trunk and extremities, the heart and limes, the 

 liver and intestines. 



The law of alternation in development should be of interest in its relation 

 to the growth of the organs, and it is important to know the relation of the indi- 

 vidual to puberty in any study of growth. There is also another law of develop- 

 ment that may be illustrated by the growth of the two types in man the hyper- 

 phylomorph and the meso-phylomorph. Two types long have been known to physi- 

 cians as the phthisic and plethoric, or carnivorous and herbivorous; they have 

 also been called the long skeleton and broad skeleton, or narrow back and broad 

 back, but it remains to be determined whether these types are the same respec- 

 tively as the hyper-phylomorph and meso-phylomorph. 



If growth depends upon placental alimentation, as stated by Godin, and 

 if the hyper-phylomorph is precocious and the meso-phylomorph retarded in de- 

 velopment, as determined by me (1914), and if the activities of the endocrinous 

 glands influence growth, further studies may reveal some association of these 

 facts, and thus enable us to link up our disconnected studies. 



Manouvrier (1902) called attention to the macroskeles (long skeleton) and 

 the brachyskeles (broad skeleton) in different individuals, and Godin (19 Oa) 

 has demonstrated that these two types differ from each other in their measurable 

 components more than small individuals differ from tall ones, or men from women. 

 Every transverse diameter is greater in the broad than in the long skeleton. The 

 extremities of the broad skeleton, especially the lower, are relatively short, and of 

 the long skeleton relatively long; but the trunk of the broad skeleton is relatively 

 long, and that of the long skeleton relatively short. The difference in length of the 

 trunk in the two types increases considerably between the ages of 13 and 23 years, 

 and becomes the most striking difference in the linear measurements of the vertical. 

 These differences correspond with those between the hyper-phylomorph and meso- 

 phylomorph. The two types should be discriminated in any study of growth. 



The great growth of the extremities and of the teeth (osseous system) before 

 puberty, and the great growth of the trunk after puberty, the latter coincident with 

 the growth of the muscles including the heart, in conjunction with the activity of 

 the sex glands and the maturity of the systems of alimentation, circulation and 

 respiration, undoubtedly are of importance in relation to the growth of the organs. 



DATA. 



Heretofore it has been usual to select for study individuals who died in hos- 

 pitals, taking only accident cases or those who died suddenly or of acute illness. 

 In this way only the well-nourished would be chosen. It is as inexact to take 

 only the well-nourished as it is to take only the thin. Many factors besides the 

 pathological condition may enter into the state of nourishment. Some indi- 

 viduals are naturally thin, others naturally fat. The type of individual may 

 have an important bearing. In pneumonia the organs are as much above the 



