This Treatise is printed after the author's death, as a Memorial by 

 his friends, fellow-students and instructors, with the aid of the Johns 

 Hopkins University. It consists of his Dissertation, reprinted from the 

 copy which was accepted by this University at his examination for the 

 degree of Doctor of Philosophy in June, 1897. 



As he had made many notes on the embryology of the Cubomedusae, 

 and had hoped to complete and publish them together with an account 

 of physiological experiments with these medusas, he had described the 

 Dissertation on the title-page as Part I, Systematic and Anatomical, and 

 he went to Jamaica immediately after his examination to continue his 

 studies and to procure new material, and he there lost his life. 



