43 



quite fatal to them. When staying in the south of France, in 1904, 

 I often noticed small elongate patches on a very high wall exposed 

 to the hot rays of the morning sun. On examination one day these 

 proved to be dried remains of slugs, and later I found some speci- 

 mens in a moribund condition. It seems possible that these slugs 

 had commenced to climb the wall while the lower part was in shade 

 and on reaching the hot part the heat dried up the mucus and pre- 

 vented their further progress. I have seen slugs on a sunny wall in 

 Chiswick which had met with a similar fate. In wet weather, or in 

 damp shady places, especially in autumn, slugs may be found feed- 

 ing in broad daylight, but it is the shades of night that they specially 

 delight in. They have many times been observed at sugared trees, 

 and, like Pi/rcuiieis atalanta, they may be found at fallen fruit, 

 though they prefer to dine late. The life-history of a slug is as far 

 as is known comparatively simple. The individuals are of both 

 sexes when in their prime, but it is stated that some species com- 

 mence life in a unisexual condition, then develope into a bisexual 

 state, and finally become again of one sex, but of the opposite one 

 to that in which they began life. After pairing the animals lay 

 eggs, which produce young slugs. These at once look after them- 

 selves, and in due time become mature. The general opinion seems 

 to be that they require from twelve to eighteen months to reach 

 maturity, and may then live a few years. In order to get well 

 acquainted with them it is a good plan to keep them in a large tin 

 box such as grocers use for biscuits. Fill the box half full with 

 earth, on this we can lay lettuce leaves, a piece of bread, or a slice 

 of carrot, or apple. The cage must be kept quite moist and should 

 be well aired every day. From time to time the animals should be 

 placed in a second box, with fresh earth, so that the first box can be 

 thoroughly cleaned. By keeping them in this way and allowing 

 them to glide over a soup plate occasionally, we can get a very good 

 mental picture of the diii'erent species, and thus become able to 

 recognise them when we meet with them, much in the same way as 

 an entomologist will recognise Apamea seealis {(lidi^ma) in its various 

 fonais. All our species are well recognisable in their typical forms 

 when adult, but they vary considerably in colour and to some extent 

 in marking, especially when immature, so that in many cases very 

 great care is required in their identification. A white form is known 

 of many species, and it would be highly interesting if one could 

 bring white specimens of all the species together at the same time. 

 One could then more easily appreciate the difterences of form and 

 proportion in each species. 



It is not needful now to go into any technicalities, but it may be 

 useful just to indicate a general idea of a slug, as it will help after- 

 wards when the different species come to be mentioned. The body 

 is subcylindrical. The flat part on which the animal crawls is 

 known as the foot-sole. Lying on the top of the anterior portion of 

 the creature is the mantle or shield, which covers the heart and the 



