548 



^lALLOPHAGA 



posterior xsortion of the oesophagus. There are only four Mal- 

 pighian tubes ; in some species the basal 

 half of each tube is much dilated. The 

 two divisions of the intestine are short 

 and are separated by the intervention of a 

 glandular girdle. Salivary glands exist ; 

 Cxiebel figures what we may consider to 

 be an enormous salivary reservoir as exist- 

 ing in Menopon leucostomum. 



The testes and ovaries are of a simple 

 nature. The former consist of two or 

 three capsules, each having a terminal 

 thread ; the vasa deferentia are tortuous 

 and of variable length ; they lead into 

 the anterior part of the ejaculatory duct, 

 where also opens the elongate duct pro- 

 ceeding from the bicapsular vesicula seini- 

 nalis ; these structures have been figured 

 by Grosse^ as well as by Giebel. The 

 ovaries consist of three to five short egg- 

 tubes on each side ; the two oviducts 

 small combine to form a short common duct 

 with which there is connected a recepta- 

 culum seminis. 



The eggs of some Mallophaga have been figured by Melnikow ; ^ 

 they possess at one extremity a cover with a multiple micropyle- 

 apparatus, and at the opposite pole are provided with seta-like 

 appendages. They are very like the eggs of the true lice, and are 

 said in some cases to be suspended by threads to the hairs or 

 feathers after the fashion of the eggs of Pediculi. 



Little is known as to the development ; the young are ex- 

 tremely like the adult, and are thought to moult frequently ; the 

 duration of life is quite unknown. 



It has been stated by some writers that the mouth is truly of 

 the sucking kind, and that the Mallophaga feed on the blood of 

 their hosts. This is, however, erroneous ; they eat the delicate 

 portions of the feathers of birds, and of mammals perhaps the 

 young hair. Their fertility is but small, and it is believed that 



^ Zcilschr. vdss. Zool. xlii. 1885, pi, xviii. f. 15. 

 " Arch.f. Nalurrj. xxxv. i. 1869, p. 154, pi?, x. xi. 



Fig. 218. — Alimentary canal 

 of iJoGophorus fusoicollis. 

 (After Giebel.) a. Oeso- 

 phagus ; h, paunch ; a', 

 posterior division of oeso- 

 phagus ; c, chylitic ven- 

 tricle or stomach ; tZ,'Mal- 

 pighian tubes ; e, 

 intestine ; /, glandular 

 girdle ; g, rectum. 



