SCIENCE-GOSSIP. 



of the young .-till show appearances of having por- 

 tions of outer envelopes around them? Are not 

 the "battledore-like objects" mentioned in the 

 notes, ova, still having the filaments adhering to 

 them which attached them to the ovary?— IF. 

 Damson. 



Parasite from Humble Bee. — This belongs, 

 no doubt, to the family Gamasinae. I have a 

 number of species of this family in my possession, 

 but not this particular one. Several species are 

 found parasitic on beetles and bees. I think, on 

 referring to a written description 1 have by me, 

 that it is Gamasus coleojptratoni/m, Linn., and if so, 

 to hear its name, it ought to have been found on a 

 beetle instead of a bee. Shuckard does not men- 

 tion it in his " British Bees." I have measured 

 the body of one of these on this slide, and it 

 is 5 V of an inch long ; but in my description of 

 G. coleoptratoTum it should be only T \, so the cor- 

 rect name is doubtful. — Charles 1). Soar. 



T have kept this box a few days over time, as I 

 was much interested and pleased with its contents. 

 The scale leaf mounts are very instructive, and it 

 is a subject which has been coming to the front 

 lately. The position of the ovipositor is not shown 



Ovipositor cm Wild Bee. 



•correctly in the slide, and I have taken a photo of 

 the same object from my own cabinet to show its 

 true position. I have tried to find out what the 

 three little affairs are, but cannot get any informa- 

 tion. I see Mr. Dawson suggests that these battle- 

 dore-like objects are ova, still having the filament 

 attached. I do not think so, for this reason. In 

 Mr. Pattrick's slide there are three out of position. 

 In my photo there are also three, but in position, 

 and it seems hardly likely that there should be 

 exactly three ova in two different objects. In 

 Knowledge, of November, 1894, there was a good 

 account of the Crane Fly, or Daddy-long-legs, by 

 Mr. Butler. He says. " The hinder part of the body 

 of the female tapers regularly to a hard and sharp 

 point. This acute tip is the hardest part of the 

 body, and necessarily so, as it has to do the hardest 

 work. It constitutes an egg-laying instrument of 

 superior quality, and is composed of four pieces 

 disposed in pairs. On the upper side are two long 

 and pointed pieces wdiich form the sharp tip. and 

 are used as borers, and underneath these is the 

 other pair, considerably shorter and blunter, their 



function being to guide the eggs in their passage 



into the hole prepared I'm- them by the pair of 

 borers." The whole apparatus, therefore, is 

 thing like a combination of an auger and a spoon. 

 The photo will make this clear. When egg-laying 

 the creature balances itself on its two hind legs 

 and ovipositor, whilst the fore front legs are up in 

 the air. I send also photos of Sheep-tick and 

 ovipositor of "Wild Bee. [s this the ovipositor? 

 It is a strange one. — '/'. (I. Jefferyt. 



OVIPOSITOB of TlPULA.— Had there been only 

 two of those battledore forms one might have 

 suggested that they were the " halteres " or abortive 

 wings of the Tipula, but as there are three, that 

 suggestion will not do. The viscera attached show 

 that they are connected with some of the internal 

 arrangements. — (He-.) Adam Clarke Smith. 



MICROSCOPY FOR BEGINNERS. 



By F. Shillisgtox Scalks, F.R.M.S. 



{Continued from p. 01.) 



Instead of gold-size other cements may be used : 

 but we have found gold-size, especially if old. 

 most satisfactory, save for certain fluid mounts. 

 Bell's Cement is excellent, and so is Ward's Brown 

 Cement, whilst Mr. Cole recommends Watson's 

 Special Club Black Enamel. Marine Glue is to us 

 an abomination, and we have long discontinued its 

 use. Under any circumstance it must be applied 

 hot. 



We have dealt at considerable length with mount- 

 ing opaque or dry objects because it is the easiest, 

 and forms a natural introduction to mounting in pre- 

 servative media. There are many more or less 

 specialised methods of the latter, but it will be 

 sufficient if w T e confine ourselves to two — namely. 

 Canada balsam and glycerine jelly. These two 

 methods, and especially the first, are used univer- 

 sally. Objects or sections may need careful pre- 

 paration beforehand, but we will deal with these 

 methods afterwards, assuming here that, as fre- 

 quently happens, no such preparation is necessary. 

 Canada balsam is best purchased ready for use, in 

 which case it will be obtained as a solution in 

 benzole or xylol. It should be kept in a wide- 

 mouthed bottle, provided with a glass rod for 

 dropping the contents upon the slide, and with a 

 closely-fitting cap instead of stopper. The bottle 

 must be kept closed as much as possible. Glycerine 

 jelly is practically a mixture of glycerine ami 

 gelatine which liquefies when warmed. It can be 

 obtained in shilling bottles fitted with an ordinary 

 cork. The first important distinction to be noticed 

 between them is that whilst objects mounted in 

 Canada balsam must be freed from every trac 

 water, those mounted in Glycerine jelly must he 

 first soaked in water or some aqueous medium. 



In both cases a mounting-table and lamp should 

 be provided. The table in its simplest form is a 

 plate of brass about 4 x .'! inches, standing on four 

 legs about B or 1 inches high, and it will cost a 

 3s. 077. The lamp is a small glass methylated spirit 

 lamp, with a glass top. such as is used in laborato- 

 ries to £0 beneath the table. This can be purchased 

 for Is. 



The actual process of mounting in Canada. 

 balsam may be carried out as follows. We will 



