THE HIGHER CRYPTOGAMIA. 259 



of the neck of the archegoniuni and the closing of its mouth 

 did not take place until after the entrance of the sperma- 

 tozoa. According to his view one of those spermatozoa 

 which had first effected an entrance into the archegoniuni 

 then penetrated with its pointed end into the embryo-sac 

 which in the mean time had become multicellular; the 

 pointed end then became swollen and converted into a 

 spherical cell which gradually displaced the tissue of the 

 embryo-sac, formed new cells in its interior, and thus con- 

 stituted the embryo. He thought that the spermatozoa 

 which had entered the archegoniuni at an early period, 

 and which had not aided in the formation of the embryo 

 but had reached the canal of the neck, were there trans- 

 formed into the worm-shaped masses which I have pointed 

 out as the product of the transformation of the cells of the 

 axile string of the neck of the archegoniuni. From the 

 erroneous notion entertained by Suminski as to the de- 

 velopment of the archegoniuni, it is quite clear that his 

 observations upon the entrance of the spermatozoa into the 

 central cell must be founded on a misconception, and that 

 he never really saw the spermatozoa enter the archegoniuni 

 at all. His idea of the formation of an endosperm in the 

 embryo-sac is founded upon an incorrect arrangement of the 

 different stages of development which he observed; the 

 body which he designates as endosperm, as " multicellular 

 parenchyma filling the embryo- sac," is in fact the young 

 embryo. L. Suminski first observed the cilia of the fore- 

 end of the spermatozoa, but did not draw them quite cor- 

 rectly (1. c.j t. ii, figs. 20, 21). Thuret gave the first 

 accurate figures of them (' Ann. d. Sc. Nat./ 3rd ser., vol. 

 xi, p. 5). A succession of works by other observers fol- 

 lowed quickly upon the publication of Leszyc-Sumin ski's 

 treatise. First came Wigand in the ' Bot, Zeitung/ for 

 1849. He disputed most of the statements of his prede- 

 cessor, even those which were quite accurate, such as the 

 constant occurrence of the cavity (of the central cell) 

 beneath the free portion of the archegoniuni (1. c, p. 78) ; 

 the regularity of the pressure of the neck of the arche- 

 goniuni upon that layer of the tissue of the prothallium 

 which covers the enclosed young embryo (1. c, p. 77, 106) ; 



