150 



the form of a bent cylinder or finger. Landois hade already noted 

 that the cylindrical division is ordinarily filled with spermatozoa. I 

 looked over the receptaculum seminis in other genus' of fleas 

 and came to the conclusion, that the functions of both divisions are 

 quite difl'erent. As the cylindrical division fulfills the function of re- 

 ceptaculum seminis, the globe-shaped division serves as reservoir,, 

 in Avhich infuse the secret of Lapdois's «Kittdrüsen«. Landois had 

 already seen some openings of thW small ducts in the walls of the base 

 of the globe-shaped division. The crushing out of the spermatozoa 

 from the cylindrical division in the globe-shaped division, where they 

 mix with the secret of the »Kittdrüsen«, proceeds by means of special 

 muscles, which Landois did not see, and which I show on my 

 drawing. They hold by one end to the blind end of the cylindrical 

 division, by the other end to the walls of the globe-shaped division. 

 The degree of the contraction of these muscular fibres determines 

 itself by the degree of the bent of the cylindrical division. — 



The case of the double receptaculum seminis presents a rare 

 exception among the insects. This distinction in the organisation of 

 the genital organs of Hijsirichopsylla can be considered, or as a mani- 

 festation of atavismus, or otherwise as a special independently arisen 

 distinction, which mutilates the original tipe of the genital apparatus. 

 In favour of each opinion could be found some arguments. 1 wish only 

 to indicate that Hystrichopsylla^ judging by her exterior character, 

 presents a rather ancient^type among other Pulicidae^ but generally all 

 the Aphaniptera possess a strongly special organisation, on which the 

 conditions of their parasitic life have left their sharp trace. Personally^ 

 I am more inclined to the last opinion. 



Kiew, 17. Sept. 1903. 



3. Sulla respirazione cutanea e branchiale dei Diplopodi. 



Pel Ur. Giovanni Luigi Rossi, 

 Libero docente di Anatomia comparata nella E. Università di Roma. 



eingeg. 22. September 1903. 



I. 



Nel 1901 1 io ammisi nell' lulo, in forma ipotetica, un attiva respi- 

 razione cutanea per ragioni che possono riassumersi cosi : 



1) 11 dermascheletro calcarifero è reso permeabile ai gas da una 

 infinità di poricanali che lo attraversano, a cominciare dallo epitelio 

 sottostante fino alla sua superficie libera. 



1 Sulla resistenza dei Miriapodi all'asfissia. Bullet. Soc. entern. itaL 

 anno XXXIIL 1901. 



