Nova Acta Acad. Ccesar. Natural Curiosorum. S57 



Ihe ovaries in tlie gigantic Phasma Ferula, Licht., in which his 

 discovery was first made* We are compelled, however re- 

 luctantly, to pass over every other part of his labours, m hich 

 embrace the whole anatomy of this insect, and to apply our- 

 selves solely to the one chief fact, to which all the rest are but 

 subsidiary. The ovaries, which occupy the whole length of the 

 abdomen, consist of abont 50 conical tubes, the bases of which 

 commonicate with the oviduct of each side. The tubes are 

 from 4-5 lines in length, and contain each from 8-14 eggs in 

 various stages of development, together with certain other parts 

 which appear to furnish the materials for their growth. The 

 eggs decrease in size towards the apices of the tubes, which pass 

 insensibly into a very fine elastic filament. These filaments, of 

 equal breadth throughout, are inserted at their opposite extrem- 

 ity into the dorsal vessel, with the inner lining of Avhich they are 

 unquestionably continuous. They contain a granular, medullary, 

 irregular, and frequently interrupted substance, which is con- 

 tinued from the interior of the dorsal vessel, and lies in imme- 

 diate contact with the contents of the tubes. " When these 

 filaments," observes the authour, " have once been seen, the idea 

 of a mistake can no longer exist. I have shewn them to many; 

 the connexion is so frequent, so obvious, and so circumscribed, 

 that there is no occasion to employ a microscope to be con- 

 vinced of its existence. I have never heard a second opinion on 

 the subject." 



The connecting filament, however, does not merely unite the 

 dorsal vessel with the apex of the ovarian tube ; it passes into 

 the interior of the latter, and lines its internal surface in imme- 

 diate contact with its contents, and expanding as it advances, 

 terminates near the union of the tube with the oviduct, in a free 

 edge. The portion which is thus enveloped by the tube is 

 capable of being separated from it ; it alone contains the eggs 

 and their rudiments, the filamental portion which is exterior to 

 the tube being filled with tlie irregular medullary substance 

 dejrived from the contents of the dorsal vessel. All these facts 

 are well illustrated in the plates which accompany the Memoir. 



The discovery of this extraordinary conformation in the ovaries 



Vol. III. R 



