198 JOHN TAIT. 



and the jelly-producing property must be present in various stages of 

 development in the blood-cells of different Crustacea. Crustacean 

 blood-cells offer excellent material for the study of functional evolu- 

 tion. 



Generally speaking, such studies have been much neglected in the 

 past. Keith Lucas in two notable communications (09, A, B) has 

 recently sketched the lines on which such investigation should proceed, 

 and indicated the general bearing of the results that may be expected 

 thus to accrue. I hope shortly to adduce some facts related to the 

 coagulation of crustacean blood, which further illustrate this question 

 of functional evolution. 



A considerable portion of the work recorded in this communication was done during the 

 occupancy of a table (granted by the Britisli Association and by Loudon University) in the 

 Marine Laboratory, Plymouth. The expenses of that portion of the research done in 

 Edinburgh were defrayed by the Carnegie Trust. I have to record my thanks to Dr. 

 Allen, the Director of the Plymouth Laboratory, and his assistant, Mr. Orton, for help in 

 the determination of species. 



BIBLIOGRAPHY. 



Bauer, V.— 1905, Centralb. f. PhysioL xix, p. 453. 



Caiman, W. T.— 1909, Part VII of Lankester's "Treatise on Zoology," London, 



A. and C. Black. 

 Cuenot, L. — 1891, Arch d. zool., exper., 2"'^ ser., tome 9. 

 Delage, Y. — 18S1, Arch d. zool. exper. et gen. l"^*: ser., ix, p. 166. 

 Fredericq, L. — 188.3, Ihid., 2^ ser., i, p. 413. 

 Geddes, P.— 1880, Proc. Roy. Soc. Vol. 30, p. 252. 

 Hardy, W. B.— 1892, Journ. Physiol., xiii, p. 165. 



Heim, F.— 1892, " Etudes sur le sang des crustaces decapodes," These, Paris. 

 Huxley, T. H.— 1880, "The Crayfish," Internat. Scient. Series. London, Kegan 



Paul, Trench and Co. 

 Lucas, K.— 1909, "Science Progress," No. 11, Jan., and No. 14, Oct. 

 Tait, J.— 1908, Quart. Journ. Exper. Physiol., i, pp. 247-9. 



1910, A., Ibid., Ill, pp. 1-20. 



1910, B., Proc. Physiol. Soc, June 18th, Journ. Physiol. XL. 



1910, C, Ibid. 



1911, Report Brit. Assoc. (Portsmouth), Section I. 



