88 niOCEEDINGS OF THE AMEltlCAN ACADEMY 



VI. 



CONTRIBUTIONS FROM THE ZOOLOGICAL LABORATORY 



OF THE MUSEUM OF COMPARATIVE ZOOLOGY 



AT HARVARD COLLEGE. 



No. VI.* — OX THE ANATOMY AND HISTOLOGY OF 

 AULOPHORUS VAGUS.t 



By Jacob Reighard. 



Communicated June 11th, 1884, by Alexander Agassiz. 



Material and Methods. 



The material used in the prei^aration of the following paper was 

 obtaiued from a ditch by the roadside near Fresh Pond, Cambridge, 

 Mass., in October and November, 1883. In October the surface of 

 the water was so thickly covered by a growth of Lemna as to be 

 almost entirely hidden. Upon gathering the Lemna in a shallow 

 dish, the worms could be easily collected by picking out the tubes 

 which they had constructed from the Lemna leaves. Worms obtained 

 in this way were easily kept all winter in glass jars containing water, 

 in which some additional Lemna had also been placed. They lived 

 and multiplied rapidly, even when not exposed to the sunlight. 



For sectioning, the specimens were prepared by the use of either 

 Kleinenberg's picro-sulphuric fluid, osmic acid, or chromic acid, good 

 results bein<r obtained with each. Borax-carmine, or a mixture of 

 borax-carmine and picro-carmine as recommended by Bulow for Lum- 

 briculus, was found to be the best staining fluid. The worms curl in a 

 dorso-ventral plane in the killing fluid, but they may be straightened 

 by i)lacing them on a glass slide between the edges of two square 

 cover-glasses, which are closely applied to the slide and held in position 

 by wetting their under surfaces. The straightening is accomplished 

 by sliding the cover-glasses against the worm, one on each side, care 



* No. V. of these Contributions appeared in the Quart. Jour. Micr. Science, 

 Vol. XXIV., N. S., 1884, under the title, " The Development of riirygauids, etc., 

 hy Wi 1,1,1AM Patten." 



t Prtpared under the supervision of Dr. E. L. Mark. 



