No. I.] STUDIES ON LIMULUS. loi 



work on the peripheral nervous system of Limulus more than 

 ten years ago, and have continued my observations on it from 

 time to time ever since. 



I had thus worked out the semi-maceration method of dissec- 

 tion, the structure of the large, median cardiac valve, the 

 cardiac plexuses, and the distribution of the main peripheral 

 nerves, neural and haeinal. A great deal of time was devoted 

 to the distribution of the cardiac nerves, in order to determine 

 their mode of union with the central nervous system ; also 

 much time was given to studying out the relations of the 

 longitudinal, sympathetic, and intestinal nerves. Many of the 

 results thus obtained were recorded in the shape of notes and 

 rough drawings, and the entire work was well in hand when it 

 was turned over to Mr. Redenbaugh for completion. By his 

 very careful work Mr. Redenbaugh was able to add many new 

 and important details, especially in regard to those relations of 

 the cardiac and intestinal branches that require such careful 

 dissection. All these points have been verified by both of us, 

 in some cases several times. 



The drawings were made in most instances by Mr. Reden- 

 baugh along the lines of my original plans and sketches, but I 

 have added some details of color and finish where it seemed 

 advisable to make them more distinct or more intelligible. 



The descriptive parts were written entirely by Mr. Reden- 

 baugh and are presented in very nearly the form accepted by 

 the Biological Department of Dartmouth College as a thesis for 

 the degree of Doctor of Philosophy. y^ Patten 



Most of the work in this paper has been done in the Bio- 

 logical Laboratory of Dartmouth College. We wish to acknowl- 

 edge the kindness of Commissioner J. J. Brice, and of the late 

 Col. Marshall MacDonald, for facilities afforded by the United 

 States Fish Commission Laboratory at Woods Holl, Mass., 

 during the summers of 1894 and 1896. 



