344 LEEUWENHOEK AND HIS “ LITTLE ANIMALS ”’ 
called Willem, who made such progress in drawing, through 
his father’s instruction, that there were few who could match 
him. Nearly all the plates in the celebrated work of Mr. 
Leeuwenhoek were marvellously drawn from life by him 
through magnifying-glasses. .... But hediedin the flower 
of his life on 24 January 1727, at the age of 35.” 
There is no reason to doubt the truth of this story— 
published only two years after Willem’s death in his home 
town: but it is impossible to believe that Willem van der Wilt 
drew “nearly all” (meest alle) Leeuwenhoek’s figures. If he 
died aged 35 in 1727, he must have been born in 1691 or 1692; 
and consequently he could have drawn none of the illustrations 
for the letters written in the XVII Century. He probably 
made the illustrations of the Send-brieven: but he could not 
have been responsible for any others—save some of those 
reproduced between 1700 and 1712 in the Phil. Trans. The 
pictures of vorticellids and rotifers published at the beginning 
of the XVIII Century may perhaps have been drawn by hin, 
and it may well have been Willem who made the recorded 
remark about their surprising “ wheelwork”’’.* But he must 
have been a mere child at the time. 
Whilst there is thus good reason to believe that 
Leeuwenhoek’s last letters were illustrated by Willem van 
der Wilt, there seems to be no direct evidence to show who 
drew the figures for the earlier ones. Nevertheless, it seems to 
me probable that some of them may have been drawn by his 
father Thomas. If we consider all the evidence furnished by 
Boitet, it appears to me highly suggestive. Very briefly, it is 
as follows: (1) Thomas van der Wilt was an artist living in 
Delft at the time when Leeuwenhoek wrote his early letters. 
(2) His son was employed by Leeuwenhoek to illustrate his 
later letters. (3) Thomas himself must therefore have been 
known to Leeuwenhoek.’ (4) He (Thomas) earned a good 
living in Delft not only by painting portraits, but also by 
exercising his artistic abilities in other ways. (5) Thomas’s 
father, though not a native of Delft, was a linen-draper—the 
trade which Leeuwenhoek himself engaged in. (6) Thomas 
* Cf. p. 279 supra. 
2 This is confirmed by the cireumstance—mentioned a little later—that 
Thomas was responsible for some panegyric verses elucidating the allegorical 
title-page of the Send-brieven. 
