STANDEN : OBSERVATIONS ON REPRODUCTION OF DART. 35 



March i8. — Watched them closely for three hours in early 

 morning, and am delighted to find that the animals 

 have evidently recognised uselessness of their former 

 method of approach, for now they press together side 

 by side, and genital orifices are in contact repeatedly. 

 Darts frequently used. At intervals they remain qui- 

 escent, fondling each other with tentacles and palpi, and 

 then resume their active and very remarkable movements. 

 After one particularly violent stab from the dextral snail's 

 dart, which evidently pierced deeply, the other retreated 

 entirely into its shell, and exuded a quantity of mucus. 

 By this sudden movement the dart of the dextral snail 

 was dragged out of the sac until the annulus was visible. 

 The snail then began a series of very violent efforts to 

 withdraw the dart into the sac by muscular contraction, 

 but this proving ineffectual, it deliberately turned its 

 head, and, seizing the point of the dart with its mouth, 

 tried to push it downwards. This it continued to do 

 unceasingly for twenty minutes, and finally succeeded 

 in getting the dart back into the sac. Both were quiet 

 for some hours after this, but again resumed their love- 

 making in the afternoon, and late in the evening I found 

 their darts lying side by side on the glass. 



Both snails again inert, and declined to feed for three 

 days. 



March 22. — Both again active, and eating chalk and lettuce 

 alternately, but taking no notice of each other. 



March 27. — Took out the dextral snail, and replaced it by 

 another taken from a hedgerow at Meols. 



March 28. — Again find love-making going on. 



During the next two days snails very active, but the 

 fresh one will persist in meeting the other head to head 

 in normal manner, which seems to irritate the other. 



April I. — This morning I find two darts on the glass. Do not 

 think the pair have been actually in contact, but they 



