Volume 2

Dissertations relative to the natural history of animals and vegetables / Translated from the Italian of the Abbé Spallanzani.

  • Spallanzani, Lazzaro, 1729-1799.
Date:
1789
Catalogue details

Licence: Public Domain Mark

Credit: Dissertations relative to the natural history of animals and vegetables / Translated from the Italian of the Abbé Spallanzani. Source: Wellcome Collection.

    33/528 (page 25)
    x è . DIssERTATION 1, 25 attaches itfelf to badies (xv); above thefe ap- pear two tumours, which bring to the mind the idea of eyes; and eyes appear diftinctly in a day or two, and i it then becomes necefiary to fubftitute the notign of a tadpole in the place of that of an egg. Let the reader caft his eye on No, iv. Fig. 5. and he will fee a {phere of mucus, the inclofed membrane and the tadpole not yet evolved, No. 1, 11, 111, Fig. 6. reprefents the membrane dividin g into two fegments, which when they are entirely parted, leave the tadpole No. iv. at liberty, which’ appears bent No. vi. Meanwhile the amnion is feen in the dotted circle 1. full of liquor, in which the tadpole floats. The two fegments are ftill plainer at Fig. 7. where two amnions are feen diftin&ly, one of which is entirely feparated from the feg- ments. | | xxx. But do thefe tadpoles exift before fe- cundation as in the foregoing fpecies? To determine this queftion, I had only to make a rigorous ‘comparifon between the fuppofed eggs, after and before impregnation, and I analyfed them in the fame exa& and careful manner as I had the others (xvi11), and found the moft perfe& refemblance between them; whence it was neceflary to conclude, that the fetus