DISPLAYING ENTOZOA IN MUSEUMS. 171 



that their position should be made to correspond with the atti- 

 tudes which thej assume in nature. 



2. In the case of Hydatids, and in instances where it is desired 

 to show a large mass of parasites, I have occasionally reversed the 

 above method. Thus, in place of a vertically disposed sheet of 

 mica, I introduce a circular diaphragm of the same substance, its 

 diameter slightly exceeding the width of the jar. The mica should 

 be stout ; otherwise the weight of the spirit (on the jar being moved 

 or carelessly inverted) wiU be sure to displace the diaphragm. 

 It should be carried about two-thirds of the way down the bottle, 

 and be fixed in an obliquely transverse position. The speci- 

 mens are thus suitably displayed at or near the centre of the 

 vessel. It is unnecessary to fix them to the mica ; but, if desired, 

 they may be retained in their place by a second or superimposed 

 diaphragm. Ordinarily this is not advisable. 



3. "Where the parasites are very minute, yet still sufficiently 

 visible to the naked eye to be worthy of museum display, a thin, 

 square, oblong or circular plate of mica may be applied and fixed 

 to the vertical sheet, including the objects after the fashion of 

 ordinary microscopic preparations. This seemingly simple me- 

 thod, however, required great care and patience ; for, in place of 

 using cement, it is necessary to fix the two mica jDlates together by 

 means of fine thread. In doing this the operator is liable to dis- 

 place or distort the specimens ; but when once accomplished with- 

 out disturbance, there is no fear of subsequent injury. This me- 

 thod is eminently suitable for the display of Oxyurides, Sphseru- 

 larise, and other minute Nematodes, which in our pathological 

 collections are usually seen lying at the bottom of the vessels 

 enclosing them. In some instances, as obtains in the British 

 Museum, I have seen the specimens enclosed in a secoud vessel 

 or glass tube, the one swinging within the other in a very slovenly 

 manner*. 



4. In certain cases where none of the above-described methods 

 are altogether satisfactory, I have introduced another plan which 

 I am particularly desirous of bringing under the Society's notice, 



* The Entozoa within our national collection are both numerous and valu- 

 able. At present, however, the bottles containing them are lodged within a 

 glass case, the latter being itself placed in a dark passage leading to the so- 

 called " iasect-room." The specimens have been skilfully catalogued ; but, for 

 want of space, they are huddled together without any definite or systematic 

 arrangement. For the furtherance of the interests of science they are practically 

 unavailable. It is earnestly hoped that Dr. Baird's efibrts to secure a proper 

 apartment for their exhibition may yet meet with success. — T. S. C 



