106 



SATURDAY LECTURES. 



to its burrow as above indicated. The earth-worm is her- 

 maphrodite. Yet the junction of two individuals is neces- 

 sary to liberate and fructify the ova. At certain seasons a 

 few of the rings, generally near the anterior third of the 

 body, swell so as to look much like a healing wound. Two 

 individuals join at these swollen parts, a glutinous secretion 

 aiding the conjugation. 



Fig. 15. — Lumbricus terrestris : a, worm with pale, swollen rings; b, two 

 conjoined; c, egg, natural size; d, do., enlarged, (after Curtis;) e, a few rings; 

 f, transverse section, showing spines, enlarged. (After Samuelson.) 



The young worm is born much like its parent, either free or 

 in a cyst-like covering, which subsequently bursts-r-the 

 nature of the soil having apparently something to do with 

 the difference. In some species a number of eggs are enclosed 

 in a single capsule. The worm, though living in the earth, 

 is really semi-aquatic. It will live a long while in water, 

 but soon dies when exposed to the dry air. It delights most 

 in damp soil, and takes advantage of rains to travel at night 

 on the surface, and in earfy spring it is often allured in great 

 numbers on to the warm pavements of our city, where many 

 perish if the weather becomes suddenly cold or the pave- 

 ment dries out too rapidl3^ The earth-worm hibernates at 

 the bottom of its burrow, which may extend from three to 

 six feet in a light soil ; it also remains coiled up in a state 

 of torpor during very dry weather. It is by no means de- 

 void of sense or intelligence ; but it is as an agent in indi- 

 rectly promoting man's welfare that this humble creature 

 performs a part that few suspect. The same genius who so 

 profoundly influenced modern scientific thought by the 



