82 SCIENCE PROGRESS. 



futuri anni Bracteas, sequentis Calycem, insequentis Corol- 

 lam, consequentis Stamina, subsequentis Pistillum, re- 

 fertum Medulla granulata Seminum, termino vitae vege- 

 tantis." Then again the appendix to his Pkilosophia 

 Botanical entitled " Metamorphosis vegetabilis " contains 

 the following aphorism : " Principium riorum et foliorum 

 idem est ". The full bearing of these passages can, however, 

 only be appreciated when his theory of " Prolepsis," or an- 

 ticipation, is understood. This theory is set out at length 

 in two dissertations, both bearing the title " Prolepsis Plan- 

 tarum," 2 but the earlier one is the more important. The 

 starting-point of the theory seems to have been the observa- 

 tion that when a tree or shrub is planted in a pot, it flowers 

 and fruits annually ; whereas if planted in open ground, it 

 produces branches and leaves abundantly, but no fruit. 

 Hence Linnaeus infers that in the latter case leaves are 

 produced in the place of the flowers in the former : and 

 conversely, when such a plant is transferred from the open 

 ground into a pot, flowers are produced in the place of 

 leaves. He concludes that in the production of a flower 

 there is an anticipation {prolepsis) of what would represent 

 several years growth of vegetative shoots. The way in 

 which he works out this idea, and forms his theory, will be 

 made sufficiently clear by the following headings taken 

 from the earlier dissertation : " Soboles praesentis anni Folia 

 esse patet per se ; Soboles insequentis anni Bracteas esse 

 patet ex Ornit/wgalis ; Soboles tertii anni est Perianthium 

 (Calyx), quod patet ex Luxuriantibus ; Soboles quarti anni 

 Petala, quod patet ex Proliferis ; Soboles quinti anni 

 Stamina esse, patet ex Plenis; Pistillum staminibus ex- 

 haustis, esse ultimi anni folia a Plenis et Carditis." This 

 idea, crude as it is, involves the assumption that the organs 

 assigned to each successive year are equivalent ; and 

 Linnaeus frequently designates them by the common term 

 "folium ". 



It may seem strange that, having gone so far, Linnaeus 



1 Philosophia Botanica, 1 75 1 ; third edition, 1790, p. 301. 

 2 " Prolepsis Plantarum " (Ullmark), 1760, in Amoen. Acad. vi. ; 

 "Prolepsis Plantarum" (Ferber) 1763, ibid. 



