398 Annals Entomological Society of America [Vol. IX, 



The next reference is to be found in the classic work of 

 Straus- Durckheim on a scarabaeid, Melolontha vulgaris, which 

 was published in 1828. 



Leon Dufour seems to have been the first man who did 

 extended work on the Malpighian vessels of insects, and was the 

 first author to point out the fact that the posterior intestinal 

 insertion of the Malpighian vessels is only superficial. In 

 discussing the metamorphosis of Mordella fasciata (Coleoptera) 

 he wrote in 1840: "* * * I have always thought that this 

 insertion penetrated the tunics of the coecum or the rectum in 

 such a manner that the vessels might discharge a portion of 

 their products of secretion into the interior of the latter. It 

 is thus that all entomotomists have regarded this point of 

 anatomy. * * * The posterior or coecal insertion of the 

 hepatic vessels of the larva of Mordella (and perhaps or probably 

 of all insects) is only superficial. These vessels instead of 

 emptying into the intestine * * * simply ramify and 

 are lost in a hyaline membraniform tissue which surrounds 

 it. * * *" (Pages 231 and 232). 



Dufour published a memoir on the Malpighian vessels in 

 1843, in which he discussed this double insertion still further, 

 and described the conditions as he found them in several 

 chrysomelids. In speaking of Donacia, he said in part: " * * * 

 These vessels, which lack a rectal insertion, differ between 

 themselves in size and the manner of insertion; they have 

 * * * only a ventricular insertion, and although they 

 appear to be six in number, there are really but four vessels. 

 Two, much thinner and handle-like (a anses) are inserted by 

 their four ends into an ovoid sessile body, which is a sort of 

 gall-bladder (vesicule biUaire) ; two others, shorter, larger, 

 swollen, large-belHed (ventrus) in the middle and floating at 

 one end, are implanted isolated at the extremity of the ventri- 

 culus on its superior face. " (Page 156). In Crioceris merdigera, 

 "* * * the rectal insertion takes place by two trunks of two 

 branches, and by two isolated vessels; and the ventricular, 

 first by a lateral gall bladder as in Donacia, which receives 

 four vessels, and then by two other more delicate vessels, 

 colorless and isolated." (Page 157). "In Cassida the four 

 principal vessels are grouped, but not confluent for their 

 ventricular insertion; this takes place in the ventral wall of 



