MEMOIRS 



READ BEFORE THE BOSTON SOCIETY OF NATURAL HISTORY 



I. The Sigxificance of Bone Stuuoture. 

 By Thomas Dwight, M. D. 



Parkman Professor of Anatomy at Harvard University. 

 Eeiid March 3, 1880. 



XT is not easy to determine who first appreciated the fact tliat the spongy tissue of 

 bone is not a meaningless tangle but an architectural structure. The late Professor 

 Jeffries Wyman read a paper "On the Cancellated Structure of some of the Bones of 

 the Human Body" before this Society on Isov. 7, 1849. He stated that there is a ref- 

 erence to the matter in Ward's " Outlines of Human Osteology," which was published 

 in London in 1838. He, however, gave the credit of first calling' attention to the sub- 

 ject to Bom'gery and Jacob (1835). Professor Wjnnan wrote as follows: "The cancelli 

 of such bones as assist in supporting the weight of the body are arranged either in the 

 direction of that weight or in such a manner as to support and l)i-ace those cancelli which 

 are in that direction. In a mechanical point of view, they may be regarded in nearly all 

 these bones as a series of ^studs' and Mn-aces.'"' He thought that the arrangement in 

 some of the human bones is characteristic and has a definite relation to the erect position. 

 "As a rule the strength of the bone seems to he oljtained in other mauunals at the ex- 

 l^ense of its lightness by giving greater thiclaiess and density to the outer shell, as well 

 as by stouter cancelli with smaller areolae." He found Ijut sliglit traces -of a corre- 

 sponding plan in other animals; a conclusion that seems surprising on the part of so 

 acute an observer. 



Professor Humphry di-ew attention to the mechanical advantage gaiiied by the ar- 

 rangement of the cancelli in his treatise on the human skeleton published in 18;">8. 



Professor Hermann v. Meyer'^ of Zurich announced this discovery anew in 18G7 and is 

 generally looked up to as the first to grasp the idea. He certainly deserves the credit of 

 having studied it more thoroughly than any of liis predecessors. He thought that the 

 cancellated tissue could be divided into two types, that fitted to resist pressure in one 

 direction, and that fitted to resist it in many. The discussion was taken up witli great 

 interest l)v (Jermau anatomists. 



'Boston .Journal of Natural History, Vol. vi. ^Reiclicrt und DnBois Reymoud's .\rcliiv, 18G7. 



JIEMOIRS HOSTQN SOC. NAT. HIST., VOL. IV. 1 (1) 



