304 OBSERVATIONS ON WORMS. 



garden in that town, after an exceedingly hard storm, 

 and under circumstances that at first sight seemed to 



He believes also that it was these worms which Audouin found in 

 considerable quantity in the larvae of the cockchaffer, of which 

 Dujardin conceives them to be the parasites, during the first stage 

 of their existence. And this serves to explain why the worms 

 have been only met with in certain seasons, as appears to be the 

 case. He supposes that, the larvae of the cockchaffer being 

 many years in coming to their full growth, their intestinal worms 

 would, like them, shew themselves more abundantly some years 

 than others. We may explain also (he adds) why it is generally 

 on the surface of the earth in gardens, where these larvae live at 

 a certain depth, that the Mermis shews itself in the spring, when 

 the earth has been disturbed, or softened by rain : their appear- 

 ance is furthermore occasioned by the moisture stimulating the 

 larvse already sick to expel their parasites by contraction, and 

 thus allowing the Mermis to get free, in order to deposit its eggs 

 upon the ground, without being dried up. 



Dujardin is of opinion that many of the long filiform worms, 

 reported to have been found in the bodies of different caterpillars 

 and insects, have been really species of Mermis, the colour of 

 which, becoming more and more dark according to the degree of 

 development of the ova, has led to their being confounded with 

 the true Gordius, as well as the circumstance of their being able 

 to live a considerable time in pure water. 



He has himself kept the Mermis in water for more than eight 

 days ; but he has always observed that the deepest-coloured indi- 

 viduals tried to escape from the water, with a view of depositing 

 their eggs in dry places, where they soon died. When the worms 

 are not pressed by this necessity, he states that they can subsist 

 for a much longer time in pure water ; and this is precisely the 

 case with those that have been drawn from the bodies of larvse or 

 living insects. 



The above is an abridged extract fromDujardin's account of the 

 habits of these worms. He has followed it up with a very 

 detailed description of their anatomical structure and the cha- 



