\ \B * A* y 



Of THE 



UNIVERSITY 



CH. I] EARTHWORMS AND LE 



influences which we perhaps should designate as tastes, 

 e.g. a grain of salt touching any part of the worm's body 

 causes severe discomfort and strong pungent smells as 

 of ammonia are perceived equally well by all parts. Such 

 stimuli as these can, however, not be regarded as natural, 

 and it is not inappropriate to recall the fact that while 

 we ourselves taste salt and smell ammonia we are keenly 

 aware of their presence on any moist thin portion of our 

 skin, e.g. the surface of the eyeball, or on spots whence 

 the skin has been abraded. 



Reproduction. The worm is hermaphrodite, possessing 

 both male and female organs, and when sexually mature 

 may be known by the development of the ' cingulum ' 

 or 'clitellum,' the thickened ring girdling the body for 

 some 6 or 7 segments and popularly regarded as the scar 

 marking recovery from bisection with a spade ! There 

 is no very clearly denned breeding season, for worms may 

 be found in the act of mating at any time from spring 

 to autumn, provided the weather be suitable ; warm, moist 

 days being the most favourable. In L. terrestris the 

 reproductive organs consist of two pairs of spermathecae in 

 segments 9 and 10 respectively, two pairs of testes in 

 segments 10 and 11 contained in a median vesicula 

 seminalis, and three pairs of lateral vesiculae seminales in 

 segments 9, 10 and 11. In the vesiculse the spermatozoa 

 mature, and from them are conducted out of the body by 

 the vasa deferentia opening on the 15th segment. There 

 is a pair of ovaries in segment 13 ; the ova are passed out 

 of the body by the short oviducts, whose internal apertures 

 are in segment 13 ; the external in segment 14. The ova 



