2*8 



NA TURE 



[January 4, 1906 



.i nymph, a stage roughly corresponding with chrysalis of 

 .1 butterfly, Phis nymph, if it has luck, again attaches 



itseli to tlif dog and has -al, bul ii also fails to infect 



the dog. After a varying time it also drops to iIip ground, 

 undergoes a metamorphosis, and gives rise to the eight- 

 legged adult tick. Here at last we reach the infective 

 stage ; the adult tick is alone capable of giving the disease 

 to the animal upon which she feeds, and then only when 

 -.In is descended from a tick which has bitten an infested 

 host. Think what a life-history this parasite has ! Living 

 in the blood-corpuscles of a dog, sucked up by an adult 

 tick, passed through her body until it reaches an egg, laid 

 with that egg, being present while the egg segments and 

 slowh develops into the larva; living quiescent during the 

 larval stage and the nymph stage, surviving the meta- 

 morphosis, and onh leaping into activity when the- adult 

 stage is reached. This most remarkable story probably 

 nidi, ahs that tin Piroplasma undergoes a scries of changes 

 comparable to those of the malaria organism when it is 

 inside the mosquito; what these slaves are we do not at 

 present know, but Dr. Xuttall and Mr. Smedlcy at Cam- 

 bridge, ami mam other observers elsewhere, are at work 

 on the problem, and soon we shall have more light. 



With regard to bovine piroplasmosis, Koch and others 

 have distinguished redwater fever, which is conveyed by 

 Rhipicephalus annulatus, and in Europe probably by 

 Ixodes reduvius from the Rhodesian fever which is con- 

 veyed bv Rhipicephalus appendiculatus, and 1 regret to say 

 by a species dedicated to myself, Rhipicephalus shipleyi.^ 



The heartwater disease of sheep and goals is similarly 

 conveyed by Amblyomma hebraeum, the Bont tick, and 

 mam farmers accuse Ixodes pilosus of causing the well 

 known paralysis from which sheep suffer in the early 

 autumn ; and there are many others, diseases such as the 

 chicken disease of Brazil, which is so fatal to poultry yards, 

 and which is conveyed by the Irgas persicus. 



I will nc:>t weary you with more diseases. I think I have 

 said enough to show that within the last few years a Hood 

 of light has been thrown upon diseases, not only of man 

 and his domestic animals, hut upon such insignificant 

 creatures as the mosquito and the tick. I have tried to 

 show how these diseases interact, and how both hosts are 

 absolutely essential to the disease. We can now in a great 

 extent control these troubles; the old idea that there is 

 something unhealthy in the climate of the tropics is giving 

 \\a\ hi (lie idea that the unhealthiness is due to definite 

 organisms conveyed into man by definite biting insects. 

 We have at last, I think, an explanation of win* Beelzebub 

 was called the- Lord el Flies. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 

 Oxford. — Prof. Osier has been nominated by the Vice- 

 Chancellor and Proctors .n ., delegate of the Universitv 



Press. 



A decree has been approved by Convocation providing 

 that the stipend of the Sibthorpian professor of rural 

 economy shall lie 6ool. a year, independently of the income 



fr tlie Sibthorpian estate, in the years 1906 and 1907. 



This is necessary it an election is to lie made before 100S, 

 as the full endowment will not be provided by St. John's 

 College until that year. St. John's is to nominate a 

 member of the ho. oil oi electors to the chair. 



I he following elections have been made in scholarships 

 and exhibitions in natural science : — Balliol College, to a 

 Brakenbury scholarship, J. S. Huxley (Eton College), to 

 a scholarship. C. Whitley (Bromsgrove School); Lincoln 

 College, he .1 scholarship, P. Pickford (Exeter School), to 

 an exhibition, E. Hancock (Exeter School); Magdalen 

 College, io a demyship, I). I.. Hammick (Whitgift 

 Grammar School, Croydon), to an exhibition, J. F. 

 Venables (Magdalen College School, Oxford); Christ 

 Church, to a scholarship, J. T. Lattey (Dulwich College), 

 to an exhibition, W. A. Alters (Aldenham School) ; Trinity 

 College, to a Millard scholarship, II. (,. |. Mosele) (Eton 

 < ollege). 



A COURSE of lectures upon modern research in the 

 psychology of memory, accompanied by the exhibition of 

 1 This happily turns out to be a synonym. 



no. 1 888, vol. 73] 



apparatus, will be given by Or. C. S. Myers in the physio- 

 logical theatre of King's College, London, on January 12 

 and the following seven Fridays at p.m. The course is 

 free to internal students of the university and to all 

 teachers. I he general course in esperimenl.il psychology, 

 accompanied by laboratory work, will be held on Saturdays, 



beginning on January 13. Particulars may I btained 



from the secretary of the college. 



I 111. London University Gazette announces that a course 

 of nine or ten lectures on the origin of Gymnosperms will 

 I., given during the Lent term by Prof. F. W. Oliver, 

 i' k s ., .11 University ('ollege on Mondays, commencing 

 on January 22. There is no fee for the lectures. Further 

 details and cards of admission may be obtained on appli 

 cation to the academic registrar at the university. Two 

 courses of lectures have been arranged for the Lent term 

 in the physiological laboratory of the university, viz. eight 

 lectures on tissue-respiration by Mr. J. Barcroft on Tues- 

 days, beginning on January 10, and eight lectures on 

 respiration by Dr. M. S. IYmhro\ on Fridays, beginning 

 on January m. 



SOCIETIES AND ACADEMIES. 



London. 



Royil Society, November 23, 1905. — "Some Ob-eivaliotis 

 on Welwitschia mirabilis, Hooker, f. By Prof. H. H. W. 

 Pearson. Communicated by A. C. Seward, F.R.S. 



Evidence is adduced in support of the view thai 

 Welwitschia is partially, il not entirely, insect-pollinated, 

 and that the processes of fertilisation and maturation of the 

 seed seem to be effected much more rapidly than in other 

 ( .vmnc sperms. 



The author supports Strasburger's view that the male 

 flowers are reduced forms of an originally hermaphrodite 

 structure. The nature of the prothallial tubes is discussed, 

 and the conclusion is that the true- interpretation of the 

 extraordinary behaviour of the fertile end of the 

 Welwitschia prothallus will be founded upon a comparison 

 with tin- corresponding portion of the embryo-sat 

 Gnctum gnemon. 



December 14, 1905. " The Araucarieae, Recent and 

 Extinct." By A. C. Seward, F.R.S., and Sibille O. 

 Ford. 



The wc rk was undertaken primarily with a view to 

 ascertain whether the genera Agathis and Araucaria exhibil 

 any of those features which are often associated with 

 survivals from tin- past ; the aim was to obtain an answer 

 lo the question : Do the existing Araucarieae afford evidence 

 if primitive characters or do (hey throw- light on the 

 phylcgeny oi the araucarian phylum? 



A comparison is made between the Araucarieae and 

 Lvcopodiales ; arguments are advanced in favour of the 

 view that this group of Gymnosperms, unlike' the Cycadales, 

 was probably derived from lycopodiaceous ancestors 

 Attention is directed to the various characters in which the 

 Araucarieae differ from other members of the Coniferales, 

 and the advisability is suggested of giving more definite 

 expression to their somewhat isolated position by sub- 

 stituting the designation Araucariales lor Araucarieae. 



Hie authors contend that the general consent which has 

 deservedly been given to the view that the Cycadales and 

 Filicales arc- intimately connected bv descent may have th 

 effect of inducing an attitude too prone to overestimate the 

 value of the arguments advanced in support of an extensio 

 of the 1 idea of a lilicinean ancestr\ to other sections of the 

 ( lyninosperms. 



" On the Microsporangia of the Pteridosperms. " By 

 R. Kidston, F.R.S. 



The conclusion arrived at is that the Cycadofilices, which 

 long antedated the advent of true ferns, cannot have been 

 derived from them, but are themselves the oldest type of 

 fern-like plant at present known. In regard to the true 

 ferns, it seems probable that they nun have been derived 

 from the Botryopterideae. 



" The Mammalian Cerebral Cortex, with Special Refer- 

 ence to its Comparative Histology. L, Order Insectivora. " 

 B\ Dr. (o A. Watson. Communicated by Dr. F. W. 

 Mott, F.R.S. 



