Volume 11

Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden.

  • Antonie van Leeuwenhoek
Date:
1939-
Catalogue details

Licence: Public Domain Mark

Credit: Alle de brieven van Antoni van Leeuwenhoek / uitgegeven, geïllustreerd en van aanteekeningen voorzien door een Commissie van Nederlandsche geleerden. Source: Wellcome Collection.

    53/406 (page 37)
    one hundred and twenty of the young Oysters lay in a row end to end, they would reach to the length of one inch12). If we now take these Oysters to be round bodies and we multiply the number of one hundred and twenty three times, this will yield a number of seventeen hundred and twenty-eight thousand, and consequently a ball whose axis is only one inch will be 1728000 times greater than a young Oyster, or in other words: the said large number of young Oysters only have the size of a round sphere whose axis is one inch13). The day on which I made these observations five distinguished Gentlemen came to visit me and I showed them the said young Oysters; they were also greatly amazed about the perfection of these small and neat creatures. Out of other Oysters I also removed young Oysters indeed, but the number was not by far so large, and in others again I could not discover any young Oysters14). I had kept four Oysters, which I opened the next day, and among those there was one in which the number of the young Oysters was so great that it exceeded the others, and I estimated the number by a rough guess at three to four thousand15). I further examined the small amount of water which had flown out of the Oysters into the Pot in which they had lain, and in this water I also discovered a few young Oysters. I also paid heed to the ordinary water that is in the shells of Oysters; and I dis¬ covered therein quite a great number of little Animalcules, which in bigness and figure were like the little Animalcules which are everywhere found in canals, rain- 12) The size of the oyster larvae in the Oosterschelde varies from about 0.175 mm when they are released from the mother oyster to about 0.3 mm at the end of the metamorphosis. L.’s specimens had an average size of about 0.217 mm. [Fee.] An inch is 2,61 cm. >3) The calculation is correct. L. here uses the theorem that the capacities of similar bodies are in the proportion of the third powers of homologous lines, here the axes. See Dijksterhuis, „Mathemat¬ ics”, p. 447. 14) It is possible that the first-mentioned oysters had already released some larvae and that the oysters which contained no larvae were in the male phase. The oyster is hermaphroditic, the initial phase usually being male, which later passes into the female phase. [Fee.] 15) This number is by no means excessive. An adult oyster may - dependent on its age - produce to 750,000 or 1,000,000 larvae. Most of them are eaten by other marine animals during the pelagic stage or perish in some other way. [Fee.]