THE DUCTLESS GLANDS. 173 



gland is frequently absent, or at least is not to be detected, at certain 

 periods of the year (in certain states of nutrition?). 



Drs. Halpenny and Gunn are engaged in experimental work upon 

 the thyroid and parathyroid. The results of a series of' extirpation 

 experiments upon monkeys are recorded in the ' Quart. Journ. of 

 Exp. Physiol.,' vol. iv., No. 3 (1911). The effects differ in some 

 respects from those reported by Horsley and by Vincent and Jolly. 



Drs. Gardner and Mothersill have been occupied with extirpation 

 of the adrenals in the dog, and the effect of such extirpation upon the 

 chromaphil tissues which are left behind. So far as the experiments 

 have gone they appear to indicate that when the animal survives for 

 some time with a minimum of adrenal substance, there is a notable 

 hypertrophy of the abdominal chromaphil body. 



The pituitary bodies of the monkeys whose thyroid apparatus was 

 removed are being examined histologically, but the work is not 

 sufficiently advanced for a report. 



The Committee ask to be reappointed with a grant of 40L 



Electromotive Phenomena in Plants. — Report of the Committee, consist- 

 ing of Dr. A. D. Waller (Chairman), Mrs. Waller (Secretary), 

 Professors F. Gotch and J. B. Farmer, and Drs. V. H. Veley and 

 F. O'B. Ellison. 



The purpose for which this Committee was originally appointed has 

 gradually become transformed from the particular investigation of the 

 ferments involved in flowering to that of the electrical changes asso- 

 ciated with fermentation of plants. In our last report we described the 

 associated chemical and electrical phenomena that characterise the pro- 

 duction of hydrocyanic acid in the cherry laurel (Prunus laurocemsus). 



We have continued our observations during the past year, more 

 especially as regards the nature of the electrical changes involved. The 

 results of our investigation, which is not yet finished, are contained in 

 two papers, the first of which has been communicated to the Royal 

 Society. A second paper is in preparation. 



In pea and bean seedlings the normal electric current runs from 

 the cotyledons up the stem and amounts sometimes to 0'08 volt. The 

 blaze current runs from the growing tip of stem towards the cotyle- 

 dons. 



Cutting the stem across causes a current from the cut end of 0'02 

 volt or more, which subsides in about half an hour. 



A sharp touch sends a current from the point touched and, as 

 Dr. Waller has shown, the touch of a fine hair on young stems will 

 cause an electrical current from that point. 



A series of observations was taken on the relative effects of water, 

 salt solution, ether, and chloral on the blaze currents, using hyacinth 

 root tips as the object to be studied. 



In the water the blaze increased from 0*0080 volt to - 0300 in three 

 days ; in salt solution it decreased from O0080 volt to O'OOiO ; in ether 

 from 0-0070 volt to 0"0013 ; and in chloral from 0-0020 volt to 0-0001. 



