X FEANKLIN STOEY CONANT. 



accurate observation and of exact description ; and, while short, are 

 valuable contributions to our knowledge of this widely distributed but 

 difficult group. 



As he appreciated the value to one who has devoted himself to zoology 

 of thorough acquaintance with physiological problems and the means for 

 solving them, he wished, after he had completed his general course in 

 physiology, to attempt original research in this field ; and, at the sugges- 

 tion of Professor Howell, he, in company with H. L. Clark, his fellow 

 student, undertook and successfully completed an investigation of which 

 Professor Howell gives the following account : 



In connection with Mr. H. L. Clark, Mr. Conant undertook to investigate the 

 character of the nervous control of the heart beat in decapod crustaceans. They 

 selected the common edible crab, Callinectes hastatus, and made a series of most 

 careful experiments and dissections which resulted in proving the existence of one 

 inhibitory nerve and two accelerator nerves passing to the heart on each side from 

 the thoracic ganglion. They not only demonstrated the physiological reaction of 

 these nerves, but traced out successfully their anatomical course from the ganglion to 

 the pericardial plexus. It seemed hardly probable from an a priori standpoint that in 

 an animal like the crab there should be any necessity for an elaborate nervous mecha- 

 nism to regulate the beat of the heart, but their experiments placed the matter 

 beyond any doubt, and have since served to call attention to this animal as a promis- 

 ing organism for the study of some of the fundamental problems in the physiology of 

 the heart. As compared with previous work upon the same subject it may be said 

 that their experiments are the most definite and successful that have yet been made. 



His chief completed work, the Dissertation on The Cubomedusa?, is 

 here printed ; and through it the reader who did not know Conant must 

 decide whether he was well fitted, by training and by natural endow- 

 ments, for advancing knowledge. I myself felt confident that the career 

 on which he had entered would be full of usefulness and honor. I was 

 delighted when he was appointed to the Adam T. Bruce Fellowship, for 

 I had discovered that he was rapidly becoming an inspiring influence 

 among his fellow students in the laboratory, and I had hoped that we 

 might have him among us for many years, and that we might enjoy and 

 profit by the riper fruits of his more mature labors. 



Immediately after his examination for the degree of Doctor of 

 Philosophy in June, 1897, he set out for Jamaica to continue his 

 studies at the laboratory which this University had established for the 

 summer at Port Antonio, and he there worked for nearly three months 

 on the development, and on the physiology of the sense-organs, of the 

 Cubomedusa3. 



His notes and specimens are so complete that I hope it will be 

 possible to complete in Baltimore, at an early day, the work which he 

 had expected to carry on this year. 



