KLECTRICATi PHENOMENA AND METABOI.TSM OF ARUM SPADICES. 4(37 



Coincidently with some electrical experiraertts (not sufficiently repeated 

 for any definite result), Miss Kemp took observations of the temperature 

 changes in Dracunculus vulgaris at a more active and less active portion 

 of the spadix. The accompanying figures show the course of these 

 changes in two typical cases. Miss Kemp has succeeded in locating the 

 I'egion of greatest heat rise to the anther-whorls and the short starchy 

 portion, beset with club-shaped guards, immediately below. The region of 

 the ovules is not involved, as I had previously imagined. 



The plotted curves which I gave in my first communication to show 

 the relation between rise of temperature and evolution of CO2 may con- 

 veniently be shown for comparison with those of D. vulgaris. 



c.c. CO. 

 per minnte 



1-6 



1-4 

 1-2 

 I'O 

 0-8 

 0-6 

 0-4 



O / 2 3 4 5 6 7 a 9 10 11 IZ 13 14 15 16 17 18 

 Hours. 



Fig. 3. 



Temperature curve of the spadix of Arum, italicnm from protrusion of stigmatic 

 hairs to commencement of fading. The vertiral lines at a, h, c indicate the CO, 

 production and 0„ absorption in cubic centimetres per minnte. The change is 

 more rapid and greater in species like the present, where the rise of temperature 

 occurs in the spadix than it is in Dracuiicnbis, where the starchy contents of 

 the spadix are much reduced, and the seat of change is the anther-whorl. 



(a) Enzyme Activity. — As before stated, it has been impossible to 

 take any chemical analyses owing to the lack of material. Miss M. T. 

 Fraser, B.Sc, most kindly undertook this part of the inquiry. Her 

 detailed report waits, as experiments are still going on. She began by re- 

 peating Miss Kemp's work of last year with slightly different conditions ; 



H H 2 



