528 ScHAKFF — On the Slugs of Ireland. 



A Paper dealing with the anatomy and histology of the alimentary canal and 

 the nervous system has recently been published by Dr. Hanitsch (12). 



Beproditciion. — The eggs are globular and perfectly transparent, measuring 

 2 mm. in diameter. The specimens I kept in captivity produced only about 

 30 eggs each, but according to some authorities the same slug may deposit a large 

 number during a short period. Thus, Moquin-Tandon (26) mentions that one 

 specimen has, at different times, produced as many as 300 or even 350 eggs ; 

 and, according to the same authority. Leach is stated to have observed two slugs 

 deposit 776 eggs. Although, no doubt, this slug is extremely prolific, I ven- 

 ture to think that further experiments are needed to confirm these observations. 

 The young do not seem to me to present any appreciable differences from the 

 adults. 



I have taken specimens with fully developed reproductive organs from March 

 to December. In the latter month and January the large specimens seem to die 

 off, but it is difficult to determine their length of life. Simroth (38) believes that 

 they live only one year. 



Hahitai. — AgrioUmax agrestis is to be met with everywhere. It is the com- 

 monest, and probably the most destructive of all slugs. The damage done by it 

 in the garden as well as in the field is enormous. It begins its ravages in the 

 evening soon after sunset, and feeds the whole night through until the morning, 

 when it retires for the day into worm-burrows or underneath stones and clods of 

 earth. It seems to be little affected by weather or climate, being equally com- 

 mon on the islands of the west coast, on the mainland, and on the continent of 

 Europe. 



This slug is very active, and when touched, it glides through the fingers, 

 leaving a mass of milky slime behind, and rapidly crawls away. As I have men- 

 tioned, I have seen the very dark variety only from the Aran Islands. The dark 

 slate-coloured variety, described by Clarke (3), only once occurred to me along 

 the high road to Whitechurch, near Dublin, and there were plenty of them on 

 the spot. 



Food. — AgrioUmax agrestis is very voracious and omnivorous, but I think 

 green food is preferred. In captivity they seemed to relish anything they were 

 offered, and in this respect they are very different from most other slugs. In the 

 garden I found them chiefly injurious to peas. They will eat the young shoots 

 and the flowers, and even devour the pods. I doubt whether they do much damage 

 underground to bulbs, which are chiefly preyed upon by Amalia carinata. 



General Distribution. — Great Britain, and throughout continental Europe, Asia 

 Minor, Persia, Siberia ( ? ), Japan, Iceland, Greenland, the Azores, Madeira, 

 Marocco. It has probably been introduced on the east coast of N. America, in 

 Brazil, South Africa, and New Zealand. 



