24 PI10CEEDING8 Ol' THE 



Another pertinent question is as to whether or not Linnaeus may 

 be considered to have materially contributed to the discovei'y of 

 sexuality in plants. In his prize essay, the ' Disquisitio de Sexu 

 Plantarum ' (J 760) he says that it is very difficult to say who first 

 made this discovery. Ear iVoni laying any claim to it himself, he 

 mentions Millington, Grew, Kay, Camerarius, and Vailhint as 

 moderns who had more or less clearly stated it. What still remained 

 to be determined was the mode of impregnation. That it is 

 attributable to the pollen was no longer a matter of doubt. 

 Vaillant (1718) had expressed the opinion that it was effected by 

 the transmission to the ovules, not of any material substance, but 

 of a volatile essence exhaled by the pollen-grains. On the other 

 hand, Morlaud (Phil. Trans. 1704) asserted that the pollen-grains 

 pass bodily down the style into the ovules, there giving rise to 

 embryos. Needham, in his 'Microscopical Discoveries' (1745), 

 pointed out that it is impossible for the pollen-grains to reach the 

 ovary, and asserted that the farina, falling on the heads of the pistil, 

 dissolves in the papillaD, and the subtlest of its ])arts only pene- 

 trates into the tubes leading to the ovary. The chief contribution 

 made by Linnams is contained in the dissertation ' Sponsalia 

 Plantarum ' (174G : Amoon. Acad, i.), where it is clearly laid down 

 that the pollen-grains of plants correspond to the spermatozoa of 

 animals, an inaccurate statement and yet an approach to the truth. 

 Like JVeedham, Linnaais denied that the pollen-grains descend 

 into the ovary, rightly stating that they remain on the stigma, 

 where, he thought, they burst and set free their contents, which 

 penetrate to and fertilize the ovules (cf. ' General io ambigena,' 

 Amoon. Acad. vi.). This is an advance, but not a considerable 

 advance. At the same time it must be recognized that by his general 

 treatment of the subject he established the theory of sexuality 

 upon a sounder basis and in a clearer light than did any of his 

 predecessors. 



We come now to the consideration of a more debatable matter — 

 the share of Linnanis in the progress of Plant-Moi*phology, the 

 side of botanical science that regards the parts of plants in the 

 abstract, that considers them from the point of view of tbeir 

 develo|)ment and nuilual relations rather than from that of their 

 lunclious, that determines their homologies rather than their 

 analogies. Without going far buck into ancient history, it may 

 be stated that the foundation ol' modern plant-morphology was 

 laid by Joachim Jung in his remarkable \\ orks, the ' Doxoscopia,' 

 tirst published in 1()(32, and tlu> ' Isagoge Phytoscopica,' first 

 publislied in I 67!K Li these works are to be found a clear analysis 

 ol' the plant-body iuto its constituent members, a description of 

 the members witii a precise nomenclature, and a recognition of 

 the essential similarity between the foliage and tloral leaves. 

 Although the works of Jung were not much quoted by Linnaeus, 

 yet, as we know, they were included in his library, and, moreover, 

 the id(>as and terminology of Jung were fully set out in the first 

 volume of Kay's ' ilistoria Plantarum,' a work with which Linu»us 

 was familiar. In these circumstances there can be little doubt 



