284 



NATURE 



[April 28, 192 1 



a very restricted region of the insect, being confined 

 to the respiratory system, and only to those tracheae 

 which are associated with the anterior pair of 

 spiracles. All stages of the Acarine were met with — 

 eggs, larvae, and adults i Jthey occur within the tracheal 

 tubes extending from the spiracles inwards. The 

 tracheae become darkened and ultimately black by 

 the increasing deposition of chitm. 



In studying the pathology of the disease Mr. P. B. 

 White points out that the mites perforate the tracheae 

 and live upon the body fluids of their hosts, and he 

 also raises the question, which is extremely difficult to 

 answer, whether they exercise any toxic action also. 

 When present in large numbers they entail the ob- 

 struction of the respiratory system of the head and 

 thorax, thereby reducing the efficiency of the respira- 

 tory exchange of the organs supplied. In order to 

 •obtain some idea of the effects actually arising from 

 the mechanical obstruction of the spiracles, a series 

 ■of experiments was carried out upon healthy bees. 

 The first spiracle of one or both sides of each bee 

 was closed by means of melted paraffin-wax. Upon 

 closure of one spiracle the experimental bees at once 

 lost the power of flight, but otherwise remained 

 active in their movements. After a lapse of several 

 ■days the bees became more sluggish, and about the 

 sixth or seventh day examples were noted with dis- 

 located wings and other features which commonly 

 accompany Isle of Wight disease. The thoracic 

 musculature in many cases exhibited atrophy of the 

 same type as had been found in bees infected with 

 the Tarsonemus. In those experiments in which the 

 first spiracle of each side was closed the power of 

 flight was at once lost as before, but after twenty-four 

 to forty-eight hours the bees developed a reeling 

 •gait and appeared to be continually falling over their 

 •own heads. It was seldom that any survived the 

 third day. 



As Mr. White points out, though too close a parallel 

 must not be drawn with the natural disease, these 

 experiments give a basis to the view that the rdle of 

 the Tarsonemus in partially preventing thoracic 

 respiration is of prime importance in the disease, 

 possibly in itself capable of occasioning all the 

 svmptoms by which we are wont to diagnose the 

 disease and the muscle atrophy so often associated 

 with it. 



There is evidently much still to be discovered; we 

 know as yet very little concerning the migratory stage 

 •of the parasites, and provisional experiments in pro- 

 ducing artificial infection have so far yielded incon- 

 clusive results. The reason for the parasite selecting 

 the first pair of spiracles as its sole means of entry 

 also needs elucidation. The authors of these re- 

 searches are to be congratulated upon their dis- 

 coveries, and it is quite evident that the whole sub- 

 ject of bee diseases is the most pressing problem in 

 apiculture in this country to-day; in fact, the future 

 of bee-keeping is dependent upon their thorough 

 investigation. 



University and Educational Intelligence. 



Cambridge. — Prof. F. G. Hopkins has been elected 

 to the Sir William Dunn professorship of bio- 

 chemistry. 



Sir Napier Shaw will give the Rede lecture on 

 June 9 on the subject of "The Air and its Ways." 



Mr. H. G. Carter has been appointed curator of 

 the herbarium. 



It is proposed to make a grant of 75Z. from the 

 Worts Fund to Prof. Seward towards defraying the 



NO. 2687, VOL. 107] 



expenses of an expedition to Greenland undertaken by 

 Mr. R. E. Holthurn and himself for the purpose of 

 collecting fossil plants from Cretaceous and Tertiary 

 rocks on Disco Island and the mainland and of study- 

 ing the recent vegetation. 



Steps are being taken towards an agreed solution 

 at an early date of the problem of the position of 

 women in the University. It is already clear, how- 

 ever, that the latest proposal will not be acceptable 

 to a considerable section of University opinion, though 

 it may carry with it moderate opinion, and also secure 

 the support of those who voted in December for 

 Report A. 



London. — The following public lectures will be 

 delivered at King's College during the Easter term. 

 Admission to public lectures is free and without ticket, 

 except when otherwise stated : — A course of three 

 lectures on Wednesdays, May 18 and 25 and June i, 

 at 5.30 p.m., by Prof. A. P. Newton, on "The Uni- 

 versities of the Dominions and the United States of 

 America." 



In the department of science a lecture or lectures 

 will be delivered by Prof. Einstein early in May. The 

 date and title will be announced later. 



A course of four lectures on Tuesdays, May 3, 10, 

 17, and 24, at 5 p.m., by Mr. J. H. Jeans, secretary 

 of the Royal Society, on "Cosmogony and Stellar 

 Evolution." 



In the department of philosophy a course of four 

 lectures on Tuesdays, May 10, 17, 24, and 31, at 

 5.30 p.m., on "The Present Issue between Realism 

 and Idealism," by Prof. H. Wildon Carr. 



In the department of engineering a course of four 

 special lectures for post-graduate and other advanced 

 students on Tuesdays, beginning May 3, at 5.30 p.m., 

 on "Cascade Work in Induction Motors," by Mr. 

 L. J. Hunt. This course is free only to the regular 

 students of the faculty of engineering. 



A HOLIDAY course in geology will be held at the 

 School of Metalliferous Mining, Camborne, Cornwall, 

 on July i8-August 27. The course will deal with 

 economic geology, with special reference to West 

 Cornwall, and will consist of lectures and laboratory 

 and field work. The programme includes the mapping 

 of areas both on the surface and underground, a 

 number of excursions to localities around Camborne 

 of interest to geologists, and work in the school 

 dealing with rock-forming minerals, rocks, the 

 mechanical analysis of alluvial sands, and methods 

 of dressing the products. Students wishing to enter 

 for it should apply to the Registrar, School of Metal- 

 liferous Mining, Camborne. 



It is announced that Prof. E. Cohen, of Utrecht, 

 will give two lectures on " Metastability of Matter 

 and its Bearings on Chemistry and Physics," probably 

 at University College, London, on May 10 and 12 

 at 5.30 p.m. Two lectures by Prof. H. E. Armstrong 

 on "Enzymes in Relation to Plant Growth" have 

 also been provisionally arranged; they will be de- 

 livered at King's College on June 3 and 10 at 5 p.m. 

 Another course, of three lectures, by Prof. E. W. 

 MacBride, on "Recent Advances in Experimental 

 Embryology," will probably be given at the Imperial 

 College of Science and Technology on June 7. 8, and 

 q at z, p.m. These courses of lectures are intended 

 for advanced students of chemistry, agriculture, and 

 zoology respectively and others interested in these 

 subjects. In all cases admission will be free and 

 without ticket. 



