Volume 2

Dissertations relative to the natural history of animals and vegetables / Translated from the Italian of the Abbe Spallanzani ... To which are added two letters from Mr. Bonnet to the author.

  • Spallanzani, Lazzaro, 1729-1799.
Date:
1784
Catalogue details

Licence: Public Domain Mark

Credit: Dissertations relative to the natural history of animals and vegetables / Translated from the Italian of the Abbe Spallanzani ... To which are added two letters from Mr. Bonnet to the author. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

    18/428 (page 10)
    XL But if in this fpecies fecundation takes place out of the body of the female, fliall we fuppofe that the male ejects femen upon the eggs as they are difcharged (a) ? This, with refpedl to other fpecies, is the opinion of Swammerdam, and adopted by Roefel ; though he afterwards fays, that he can- not determine whether the eggs in the uterus are impregnated by the femen out of the body. To clear up this point, I have paid unremit- ting attention to every phenomenon. As foon as the eggs begin to be difcharged, the agitation of the female is extreme -, _ fhe darts backwards and forwards, rifes towards the furface of the water, and then finks, keeping the hind legs conftantly ftretched out, and croaking in a low voice. The male, that keeps his hind legs clofe to his body, throws himfelf into ftrange contortions, and accom- panies the croaking of the female with a kind of interrupted noife, which I cannot exprefs by words. I moreover obferved, that anob- tufe tumid point, which I fufpefted to be the penis, was elongated, and now and then brought towards the eggs neareil the vent ; but 1 could not perceive any emiffipn from this fuppofed penis. The lemen, however, might be in fuch finali quantity, or fo tranf- parent, as not to be vifible. XII. To determine the quefiion, I placed feme couples, of which the female was be- ginning to difeharge her eggs, in empty vefieis. As I knew that in thefe amphibious animals fecundation always takes place in (tf) In the frog, toad, newt, and leverai other animals, the eggs are difcharged at the extremity ol the alimentary canal. water,