October 1, 1892.] 



KNOWLEDGE. 



181 



^^ AN ILLUSTRATED '^^ 



MAGAZINE OF SCIENCE 



SIMPLY WORDED— EXACTLY DESCRIBED 



LONDON: OCTOBER 1, 1S92. 



CONTENTS. 



PAGE 



Bee Parasites— IV. By E. A. Butlee 181 



The Fuel of the Blast Furnace. By VAiGiiAN Coknish, 



M.Sc, F.C.S 183 



Grasses. By J. Pextl.i>-d Sjuth, M.A., E.Sr 1S5 



The Rev. John Michell, Astronomer and Geologist. 



By JoH.vRicHAEB Sutton, B.A.Canfcib ... 188 



What is a Nebula? By A. C. Eantaed 191 



Letters : — W. H. S. Monck ; William U. Pickekino ; 



EicnAED Inwards ... 192 



A Flake of Flint and its History. By E. Lydekkek, B.A. 



Guitub 195 



The Face of the Sky for October. By Heebert Sadler, 



F.R.A.S 198 



Chess Column. By C. D. Locock, B.A.Oxon 199 



BEE PARASITES.-IV. 



By E. A. Butler. 

 (Continued from pane 1G7.) 



TO conclude our papers on the parasites to which 

 British wild bees are subject, it yet remains to 

 consider the most extraordinary of them all, the 

 extremely aberrant beetles belonging to the family 

 Stijlopidcc. It will be best to introduce these 

 remarkable insects to our readers as they were in the first 

 instance introduced to the British scientific world, and 

 in fact, one may almost say, to the scientific world at large. 

 In the year 1802 the Rev. W. Kirby, Rector of Barham 

 in Suffolk, well known as the joint author with Spence of 

 the " Introduction to Entomology," published an important 

 monograph on British bees, a group of insects to which he 

 had devoted much study, and which he was the first to 

 properly classify and describe. It was while collecting 

 materials for this work that he came across the first 

 Sttflop.s ever recorded to have been seen by any English 

 naturalist, and in the above monograph he inserted a 

 description of his discovery in a passage which has since 

 become classical to the student of the StiiUipidir.. With 

 the acuteness of observation which distinguished him, he 

 had noticed minute protuberances on the bodies of certain 

 bees. These, he thought, were possibly mites of some 

 kind, as he well knew that such creatures are often found 

 on bees' bodies ; but whatever they might be, the mere fact 



that there was something of a mystery was quite sufficient 

 to impel him to inquire into the matter and endeavour to 

 get at the truth of it. He was thus led to his great 

 discovery, but what follows had better be told in his own 

 words. In reference to his examination of the first of 

 these little knobs, he says, " What was my astonishment 

 when, upon attempting to disengage it with a pin, I drew 

 forth from the body of the bee a white fleshy larva, a quarter 

 of an inch long, the head of which I had mistaken for an 

 Acarus." This was half the discovery, but we shall see 

 presently that Kirby was mistaken in supposing that the 

 maggot-like creature he had extracted from the bee's body 

 was a larva ; it was, on the contrary, a perfect insect, 

 being in fact the female Stylops. For many years, 

 however, it was imagined, and very naturally, considering 

 its form, to be a larva ; but further facts as they were 

 discovered were seen to be more and more difficult to 

 reconcile with such a supposition, and at last it was 

 recognized that the footless grub-like creature was the last 

 stage in an eventful history, a mature insect of an 

 extremely degraded type. 



But, as we have said, this maggot-Uke grub was only 

 half the discovery, and that the less romantic half. Mr. 

 Kirby continues : " After I had examined one specimen I 

 attempted to extract a second, and the reader may imagine 

 how greatty my astonishment was increased when, after I 

 had drawn it out but a little way, I saw its skin burst and 

 a head as black as ink, with large staring eyes and 

 antenuffi consisting of two branches, break forth and move 

 itself briskly from side to side. It looked like a little imp 

 of darkness just emerging from the infernal regions. I 

 was impatient to become better acquainted with so 

 singular a creature. When it was completely disengaged, 

 and I had secured it from making its escape, I set myself 

 to examine it as carefully as possible, and I found, after a 

 careful inquiry, that I had not only got a nondescript, but 

 also an insect of a new genus, whose very class \_i.e. order] 

 seemed dubious." This was the other member of the 

 Sti/loiis family, the active little male fully equipped with 

 wings and legs, and as great a contrast to his mate as 

 could possibly be imagined. Mr. Kirby had been extremely 

 fortunate in securing both sexes on the same occasion, 

 for the males are far less numerous than the females ; F. 

 Smith estimated that; the usual proportion was about one 

 male to twenty females. Of course, Kirby did not re- 

 cognize the two creatures as thus related to one another, 

 but looked upon one as the larva and the other as the 

 perfect insect, never dreaming that there would be such 

 discrepancy in the forms of the adult insect. As he did 

 not know anything of the life-history of his nondescript, 

 he failed to see any close resemblance between it and any 

 of the types of the usually recognized orders of insects : he 

 therefore proposed to put it in an order by itself, or at 

 least accompanied by another very similar insect, which 

 had just been discovered by a continental observer in the 

 body of a wasp, and had been thought by him to be a kind 

 of ichneumon tly. This new order was called Strepsiptera 

 (twisted wings) in allusion to the curiously bent or twisted 

 form of the rudimentary fore wings. When, however, its 

 life-history came to be unravelled, it was seen that there 

 were strong resemblances between Stylops and Meloii, so 

 that the most natural place for its family was evidently 

 amongst the Coleoptera, near to the oil beetles. There it 

 and its few relatives which have been thus far discovered 

 are therefore at present resting. 



Let us now look a little more closely at our two insects, 

 and then w'e may enquire how they came to be imbedded 

 in the bee's body in which they were found. And first as 

 to the male (Fig. 9). There are several species of 



