IS ANNUAL REPORT OF THE 



106. Sargent, P. E. — Reissner's Fibre in the Canalis Centralis of 

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 January 15, 1900. 



107. Williams, 8. R. — The Specific Gravity of Some Fresh- Water 

 Animals in Relation to their Habits, Development, and Composition. 

 Amer. Naturalist, Vol. 34, No. 398, pp. 95-108. 3 figs. February, 

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108. Castle, W. E. — The Metamerism of the Hirudinea. Proceed. 

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 figs. February, 1900. 



109. Linville, H. R. — Maturation and Fertilization in Pulmonate 

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 248. 4 pis. May, 1900. 



110. Parker, G. H. — Note on the Blood Vessels of the Heart in the 

 Sunfish (Orthagoriscus mola Linn.). Anat. Anzeiger, Bd. 17, Heft 

 1G u. 17, pp. 313-316. 1 fig. March 31, 1900. 



111. Pratt, H. S. — The Embryonic History of Imaginal Discs in 

 Melophagus ovinus L., etc. Proceed. Bost. Soc. Nat. Hist, Vol. 

 29, No. 13, pp. 241-272. 7 pis. June, 1900. 



112. Castle, W. E. — Some North American Fresh-Water Rhyncho- 

 bdellidre, and their Parasites. Bull. Mus. Comp. Zool., Vol. 36, No. 

 2, pp. 15-64. 8 pis. August, 1900. 



