:398 ON THE ORDERS 



analogy to the Chilopoda ; the form of an lulus is easily 

 discoverable in the cylindrical eruciform larvae of the 

 Triclioptera, while the apod larvae of the Hymenoptera 

 are described by the first zoologists as resembling an 

 intestinal worm in form as well as manners*. I shall 

 leaye the analogy between the Coleoptera and Ametahola 

 to be discussed in a future chapter ; only stating, for the 

 present, that so far from the other analogies being fanci- 

 ful, it can be proved by citations from the works of the 

 best entomologists that they have been severally noted by 

 them, although without any view to arrangement, or in- 

 deed any object beyond the mere mention of the fact. 

 Compare Lamarck's descriptions of the genera Blatta and 

 Lepisma, and it will be seen in how few circumstances 

 some Thysaiiura difler from the larvae of the first mentioned 

 genus. I mean few circumstances according to the descrip- 

 tion, for there is enough of dissimilarity evident to show that 

 the relation between them is only one of analogy. Let any 

 one read Latreille's description of the larva of an Heinero- 

 bius or Raphidia, and, except that it is hexapod, he may 

 easily believe tliat a Scolopendra is meant. IN ay, the greatest 

 part of the aquatic larvae of Neuroptera have false feet or 

 branchiae, which complete their Scolopendriform appear- 

 ance. The similarity between an lulus and the larva of a 

 Tenthredo is carried even to such a pitch, that the number 



' M. de Humboldt's Anatomical Account of the worm Porocephalus Cro- 

 tali, which he discovered acniering- to the oesophagus and pulmonary sac 

 of a South Ameri(?an Rattlesnake, afllords us an interesting example of the 

 relation of analogy between intestinal worms and the larvasof the internal 

 orders of insects. Nothing is more remaricabie in the metamorphosis of 

 these last, than their propensity, when larvse, to secrete fat for the absorption 

 and nutrition of the insect during the period when it is unable to eat. Now, 

 M. de Humboldt says of the abovementioned intestinal worm, " Toutle corps 

 de Panimal a L'exceplion de deux extremitcs est rempli de Jils vermifarmes 

 (Vun hlanc laileux, qui puraissenl avoir de I'avaUgie avec les lambeaux grais^ 

 senx (epiploons) qui flottent dans Vinterieur des larves des insecles^ el surlout 

 avec les ovaires pelelonnes des ^siarides." 



