188 TRANSACTIONS AND PKOCKEDINGS OF THE [Sess. Lxvi, 



great was the anabolic inertia that three stimuli of a tonic 

 character were required to elicit a manifestation of irrita- 

 bility, in this case — growth. 



This example forms a transition to the condition of the 

 dry resting seed, wliich may be taken as exhibiting the 

 most extreme case of functional inertia. The Hydrocharis 

 buds when dormant are not only living but are giving 

 manifestations of life, inasmuch as they continue to respire 

 to a slight extent throughout their dormant phase (Terras, 

 loc. cit.). In the dry seed we have an organism that is living 

 but is affording no indication of life, inasmuch as it does 

 not respire. If we regard respiration as merely an episode 

 of nutrition (Giglio-Tos, " Les Problemes de la Vie," p, 54 ; 

 "Trans. Bot. Soc. Edin.," vol. xxii., 1901, p. 45), this non- 

 respiration is what we might expect. That no respiration 

 takes place in the dry seed has been conclusively proved 

 by several interesting experiments by Kochs (Verworn, 

 " Physiology," p. 132) ; Eomanes ("Proc. Pioy. Soc," vol. liv., 

 1893, p. 335); De Candolle ("Arch. Sc. Phys. et Nat," 

 viii., '99, p. 517); P)rown and Escombe (" Proc. Eoy. Soc," 

 Ixii., '97, p. 160); and Thiselton-Dyer ("Proc Pioy. Soc," 

 Ixv., '99, p. 361). Eespiration, as Ohodat (" Bull. d. Herb. 

 Bois.," vol. iv., 1896, p. 894) points out, "is not a necessary 

 condition of life, but only a condition of its manifestation," 

 for the seed is living although not manifesting life. Even 

 in regard to the manifestation of life, respiration would 

 appear not to be a necessary condition in every case, for, 

 according to Nabokich ("Jour. Eoy. Mic Soc," 1901, 

 p. 555), it is probable that some seeds can germinate 

 without oxygen. If the air be moist, however, respiration 

 begins, and as the moisture increases the respiration rapidly 

 increases (Kolkswitz, " Ber. Deutsch. Bot. Ges.," xix., 1901, 

 p. 285). 



The dry seed may be regarded as an organism whose 

 functional inertia is infinite for any single stimulus, but 

 relatively small for a given combination of stimuli, viz. 

 heat, moisture, and oxygen, and if we add light in certain 

 cases t© the combination the response is still further 

 accelerated ; for Heinricher (" Ber. Deutch. Bot. Ges.," xvii., 

 1899, p. 308) finds that seeds of Veronica 'peregrina 

 germinate 5-8 days sooner in daylight than in darkness. 



