170 DB. T. S. COBBOLD ON THE BEST METHODS OF 



Eemarks on the best Methods of displaying Entozoa in Museums. 

 By T. Spencek Cobbold, M.D., F.E.S., F.L.S. 



[Eead June 1, 1865.] 



The Council of the Eoyal College of Surgeons having afforded me 

 an opportunity of remodelling their collection of internal parasites, 

 I have, while thus engaged, introduced a few novelties in the mode 

 of mounting the specimens, and I have ventered to think that a 

 brief notice of them might be usefully placed on record. 



Some years' experience with the practical working of museums 

 has satisfied me that for the secure and permanent closure of 

 spirit preparations no plan surpasses the old Hunterian method ; 

 but in cases where it is desired to remove the specimens for tem- 

 porary examination or redissection, the employment of any par- 

 ticular kind of jar becomes a mere matter of taste. The wide 

 glass-stoppered jars are unsightly, inconvenient, and expensive ; 

 nevertheless they are preferable to the common medicine-phials 

 now employed in the British Museum. Eetaining the Hunterian 

 plan in so far as mere closure is concerned, I would invite atten- 

 tion to the following points : — 



1. Except in cases where the specimens are large and bulky, it 

 is always advisable to attach the objects to sheets of mica. The 

 employment of mica is in itself ^o novelty, but it has been usual 

 to suspend the mineral in the jar with the specimen attached. 

 This is not necessary. It should always be fixed to the sides of 

 the jar, which may easily be done by making the mineral plate a 

 little wider transversely than the correspondiag diameter of the 

 jar. The elasticity of the mica, if not too thin, will ensure fixity. 

 I introduced this method ten years ago, and on this principle 

 mounted a series of Entozoa in the Anatomical Museum of the 

 Edinburgh University. The form of the jar may vary, but it is 

 essential that the aperture be nearly of the same diameter as the 

 body of the vessel ; otherwise, on introducing the specimen, the 

 mica sheet will be injured by too great a strain upon its elasticity. 

 For my own part, I prefer that form of jar first recommended by 

 Prof Groodsir. In this case (as shown by the preparations on the 

 table) the riiti and aperture resemble those of an ordinary hyacinth- 

 glass. This leaves a circular shelf on which Mr. Goodsir used to 

 place a bridge of stout whalebone, and by means of suspensory 

 threads the mica and specimens were attached in the ordinary 

 manner. I have long ceased to adopt this plan. As regards 

 affixing, in the case of complete specimens, it is highly desirable 



