Fig. 37. Hyi)ervitainiiu).sits .\ in the i-at . Result of 1250 I.U. per gram daily from the 

 tweiit y-fir.^^t to the t went xcislit li (la\- of age. Cross section of the mi(li)ortion of the 

 femur. Alxiut one lliinl nf the cii-cunifei'ence of the cortex ha.s uii(i(MK<iii(' no ai)i)feci- 

 able change in confoiiiiit\ to the normal growth pattei-n. If a femur of a rat is ro- 

 tated on its long a.xi.s there will come to view, on the postero-internal surface, a 

 straight outline of about tlie miihile tiiird of the shaft. 











Fi(.. ;is. il\ iicrvilaniiiHisis A in the ral. A high pnucr detail of Fig. M7 , showing 

 resoi-plion of the external surface of the cortex and ncwl\ formed ixmc internally. 



127 



