72 EDWARD DRAKE CRABB. 



I have observed three individuals copulating with one another at 

 one time, the foremost one functioning as a female, the middle 

 one as both male and female, and the third as a male. Lankester 

 ('74) and Baudelot ('63) cite instances in which several L. stag- 

 nalis were observed copulating " in chains/' and Doctors Walker 

 and Ruthven have observed the same thing in our wild snails. 

 From the results obtained by rearing snails in isolation it would 

 seem that copulation is unnecessary to perpetuate the species, un- 

 less, as some writers claim, self-copulation occurs. It has been 

 suggested (Baudelot, '63) that copulation is necesssary to cause 

 the ova to move out of the hermaphrodite gland and through the 

 female conduit. However, most of the investigators who argue 

 in favor of copulation claim that the sperms must first pass into 

 the sperm receptacle where it is assumed apparently that they go 

 through a process of ripening or are endowed with some peculiar 

 properties before they can inseminate the eggs (Pelseneer, '96; 

 Lacaze-Duthiers, '99 ; Baudelot, '63 ; Lereboulet, '62 ; Moquin- 

 Tandon '55, and others). 



Many writers cite Von Baer, 1835, as having observed a Lym- 

 ncza auricularius self -copulating (Braun, '88; Diver, '25), and 

 Klotz ('89) states that Von Karsch observed an acting female 

 while in copulation stretch its penis above itself and fertilize the 

 acting male. Klotz ('89) observed simultaneous reciprocal copu- 

 lation take place three times in wild and once in captive L. stag- 

 nalis. Kunkel observed Arion self-copulating (Robson, '23, p. 

 71). I have never observed actual self-copulation in any of my 

 stock, although I have often seen apparent attempts at self-copu- 

 lation in L. s. appressa. These attempts were always ineffectual 

 so far as I was able to determine. In several cases the isolated 

 individual might be seen at any hour of the day, and sometimes 

 at night, with the copulatory organ evaginated and turgid, and on 

 several occasions the groping male organ almost came in contact 

 with the female orifice. In one instance I observed two L. s. 

 appressa with ventral sides appressed, anterior ends reversed, ap- 

 parently attempting to copulate reciprocally. 



III. OVIPOSITION AKD VIABILITY OF EGGS. 



Wild snails lay only irregularly during the spring, summer and 

 fall months, while my isolated laboratory stock lays about every 



