166 



Anniversary Address by Sir A. Geikie. [Nov, 30, 



recognition of his numerous and important contributions to mathematics, and 

 especially to mathematical physics. He has written many valuable papers 

 on various branches of hydrodynamics, in particular on the theories of jets, of 

 vortex motion, and of revolving gravitating masses of liquid. He is the 

 author of a work on " Elasticity," now in its second edition, which is highly 

 appreciated at home and abroad, and ranks as the standard treatise on the 

 subject. In this he has incorporated various valuable researches of his own, 

 which have appeared in the ' Philosophical Transactions ' and elsewhere. 

 He has further investigated closely the circumstances of wave-propagation in 

 air, in elastic solids, and in the electromagnetic medium, and has examined in 

 particular the phenomena which present themselves at wave-fronts when the 

 motion is discontinuous. More recently he has published remarkable papers 

 on terrestrial physics, including a speculation on the origin of the present 

 distribution of land and water, and an investigation of the precise extent of 

 the inferences which can be drawn as to the internal constitution of the earth 

 from the observed data relating to the heights of ocean tides of long periods, 

 the lunar disturbance of level, and the approximate period of the small move- 

 ments of the Pole over the earth's surface. 



His Majesty has likewise approved of the award of the other Eoyal Medal 

 to Major Eonald Koss, F.E.S. 



The name of Major Eoss has become widely known on account of the 

 important investigations which he has carried out on the life-history of the 

 malarial organism and the means of preventing malarial infection. Following 

 up a clue indicated by Manson, he began, in 1895, at Secunderabad, in 

 India, under circumstances which entailed mucli difticulty and many delays, 

 an investigation as to whether the malaria parasite, discovered by Laveran, 

 passes part of its life-history within the body of a biting insect. After more 

 than two years of fruitless experiments Eoss discovered a stage of the human 

 malaria parasite in the tissues of a mosquito {Anoplwlrn) which had been 

 allowed to feed on the blood of a malarial patient. In 1898 he proceeded 

 to work out in detail the life-history of a malarial parasite found in sparrows 

 and larks in India. He traced the complicated stages in the development of 

 this parasite from its inception into the stomach of a gnat (CiUe.r fatigans), 

 which feeds on the blood of these birds, to its passage back into tlieir blood 

 through the secretion of the poison gland of the insect. At the same time 

 he furnished conclusive experimental proof of the part ])layed by the insect 

 in propagating the infection. These fundamental observations have been 

 confirmed and extended in various directions by other observers, I)oth in the 

 r.ritish Empire and elsewliore. 



Ah a practical conse(iuen(M! of the discoveries of lioss and those who have 



