94 PHILOSOPHICAL TRANSACTIONS. f ANNO 1 696. 



Microscopical Observations on Eels, Mites, the Seeds of Figs, Straivberries, 8^c. 

 By Mr. Lemuenhoeck. N°221, p. 269. 



In a letter to Mr. L. the celebrated Mr. Huygens writes ihus : 



"lam very much pleased, that the longer you labour, the plainer you prove 

 the generation of animals by seed, and not corruption, and I am also of the same 

 opinion. Concerning the generation of eels,* it seems to me very strange, that 

 you find their young ones in the womb without any sign of life ; and that you 

 make no mention of any male fishes, which perhaps may by microscopes be 

 found to be living seed. But it would be long to ask you every particular, there 

 being still left innumerable discoveries behind. We ought highly to commend 

 and admire your labour and diligence in these you communicate, by which 

 natural knowledge is daily augmented. I remain yours, &c. 



" Chr. Huygens." 



It is very true, that when I was anatomizing eels, as well as palingers or 

 silver eels, and to this very day, I never found a male eel nor palinger, or silver 

 eel, that I could call so: for all that I dissected were provided with a womb. 

 Now if there be no male kind among the eels, so the little animals of different 

 kinds, that are found in great numbers on the leaves of currants, cherries, 

 plums and roses, which some call lice, after they are found on the trees, have 

 their bodies all over beset with young ones, and each of them produce their 

 kind, although I could not discern any males of them, neither could I find the 

 least sign of copulation among them. 



Now whether this engendering also takes place in the eels, ought to be in- 

 quired into ; or whether all eels are provided with masculine seed, and so are 

 hermaphrodites, as we fancy ; as by copulation, which we sometimes see, for 

 some foetuses are thus provided : that I have not said heretofore, that I have dis- 

 covered in all eels their uomb, that I concealed on purpose, that in time I 

 might inform and satisfy myself better. 



I have now in the winter again dissected some palingers or silver eels, none 

 of those which were locked up all the winter, that they might be sold the 

 dearer in Lent ; but such as I have been very well satisfied of, that they were 

 fresh caught: and now again, in the latter end of April, I have examined 

 several of them, that I might, if possible, the better to be satisfied ; yet notwith- 

 standing all these observations, I learned no more than before. 



On tlie 10th day of June, when some little boys went down into the town 



* Eels are viviparous, the ova first hatching internally. 



