58 



CERTAIN SAND MOUNDS OF 



It is evident that Dr. Manouvrier is a believer in the transmission of acquired 

 characteristics, and through this he would doubtless partially explain the marked 

 platycnemic character of tibiae from the mounds and shell heaps of Florida, a sec- 

 tion the monotonous evenness of which is proverbial. In addition, in a discussion 

 on platycnemia following an analysis of the above quoted paper given in advance, 1 

 to an objection raised as to the level nature of the country where many American 

 platycnemic tibiae are found, Dr. Manouvrier explained that the act of climbing 

 could not always by itself be considered the cause of platycnemia, and that this 

 modification of the tibia was more probably due to the inverse action of the poster- 

 ior tibial muscle in connection with running and jumping. According to Dr. Man- 

 ouvrier, platycnemia is of somewhat less frequent occurrence and less marked in 

 very large tibiae and in the tibiae of women. 



The measurement of the tibia for platycnemia is made at the level of the 

 nutrient foramen. The index is ascertained by dividing the transverse diameter by 

 the antero-posterior diameter, the reverse of the method employed in the case of the 

 femur. Dr. Manouvrier considers as markedly platycnemic all tibiae with an index 

 below 55 ; as hardly perceptible from 65 to 69, and of the ordinary form with an 

 index of 70 and over. 2 Dr. Schmidt considers within the limits of platycnemia all 

 indices under 65. 3 



During our second exploration at Tick Island 55 tibiae were measured, giving 

 an average index of 6 3 • 9 . Two tibiae, the most platycnemic, were mates, their 

 indices being 51 and 51'7. Unfortunately, these data were obtained by the aid of 

 ordinary calipers, which allow in some cases a certain obliquit}^ of measurement. 



On our fourth visit to Tick Island the following results were obtained : 



Brown Sand, or Upper Layer. Measurement with caliper square. 



Tibiae. 



Total. 



Average Index. 



Maximum 

 Index. 



Minimum 

 Index. 



Oscillation 

 Exponent. 



Male 



Female 



Uncertain 



19 



23 



4 



62-4 

 64 4 



62.8 



704 

 73 6 

 66 8 



51-1 



54'8 



n 59-9 



2-76 

 4-67 

 2-15 



White Sand, or 



Lower Layer. 



Measurement 



s with caliper square. 



Tibiae. 



Total. 



11 



11 

 10 



Average Iudex. 



60-4 

 63-9 

 60 3 



Maximum 

 Index. 



Minimum 

 Index. 



Oscillation 

 Exponent 



Male 

 Female . 

 Uncertain 



71-8 

 74 4 

 65- 



53 5 



576 

 57- 



4-6 

 4-1 

 2-2 



ORNAMENTS, IMPLEMENTS, ETC. 



From the surface to the base of the mound, associated and unassociated with 

 human remains, were found ten arrow heads and two lance points. Of the lance 

 points one was rude and massive ; the other slender, somewhat resembling wha,t is 

 sometimes termed a drill. The material of these points is chert, hornstone and 

 chalcedony. Upon two occasions, three arrow heads were found in association each 

 time with human remains, once superficially, twice, six feet below the surface. 



1 Bulletin de la Societe d 'Anthropologic de Paris— Tome dixieme; Hie serie, Paris, 1887, page 136. 



2 Op. tit., page 130. 



3 Op. tit., page 289. 



