MUNSON: SPERMATOGENESIS OF PAPILIO. 
107 
to the fact that in Bombyx, the right and left testes, which in the larva 
are separated (as in Papilio rutulus), are united in the pupa into one 
double body as it has been described in the present work. 
In an anatomical treatise, Lyonett gives a description of the testis 
of Cossus liyniperda and states his opinion that from this body either 
the male or the female genital organ is developed, hence suggesting 
the similarity of the two during the early stages. 
Herold (’ 15 ) was one of the first to distinguish between the male 
and the female genital organs. He conjectured that the sexes are 
differentiated in the early embryo, as he found them well differentiated 
in the larva just escaped from the egg. Bonnet also claimed to have 
seen the ovary of the silkworm developed in the larva as completely 
as in the adult moth. 
The first discovery of spermatozoa is often attributed to Louis 
Ham (1677); but more usually Leeuwenhoek is given credit for this 
discovery. I find, however, in an old volume by Henry Baker ( 1743 ), 
this interesting statement which needs no comment: “At the begin¬ 
ning of the year 1678, Mr. Nicholas Hartsoeker, of Rotterdam, de¬ 
clared in a Treatise of Dioptrics, by him then published, that it was 
twenty years since he first began to examine the Semen masculinum 
of several living creatures by the help of Microscopes; that, as far as 
he knew, he was the first person who had ever done so; that he had 
found in such semen infinite numbers of Animalcules, most exceedingly 
minute, almost in the Shape of Tadpoles or young Frogs; and that 
he had made this Discovery known to all the World in the 30th of 
the Ephemerides Eruditorum, printed at Paris in the same year 1678. 
“Mr. Leeuwenhoek, in the 113th of his Epistles, dated January 1678, 
is very angry at this claim; and asserts that he himself first discovered 
the Animalcules in Semine, and sent an account thereof to the Roval 
Society in November 1677, as he proves by the Philosophical Trans¬ 
actions published in December 1677, and in January and February 
1678; Nay, he further affirms, that Letters had past between him 
and Mr. Oldenburg on this Subject in 1674.” 
Besides the extensive studies of Leeuwenhoek and Hartsoeker, the 
subject was studied also by Spallanzani, and at the beginning of the 
nineteenth century by Prevost and Dumas (’ 24 ). All these early 
observers studied merely the external form and appearances of the 
spermatozoon. They seem to have been especially interested in its 
movements and its minuteness as compared with the animals with 
