72 PRACTICAL HISTOLOGY. 



jacent fascise and muscles. The most convenient 

 source of such a delicate film is to be found in the 

 exquisitely thin and transparent tissue which invests 

 and lies between the muscles of the fore-limb of the 

 rabbit and guinea-pig. The tissue in this situation, 

 especially if taken from a young animal, is devoid, 

 of fat and not so completely overridden by the bun- 

 dles of white fibrils but that the elastic fibres and 

 the connective tissue corpuscles can be made out 

 even without the addition of reagents. The mode 

 of preparation is as follows : 



The animal having been killed by bleeding, the 

 skin is snipped through around the upper part of the 

 fore-limb and is then forcibly reflected from the limb. 

 In this operation care must be taken to avoid be- 

 sprinkling the subjacent parts with the cut hairs of 

 the animal. A piece of the tissue over or between 

 the muscles is then seized with the forceps and 

 snipped off with sharp, fine scissors.. The snipped-ofi 

 tissue shrinks immediately around the end of the 

 forceps and appears very unsuited for microscopical 

 examination. But place it on a clean slide, without 

 the addition of any fluid, and with a pair of mounted 

 needles endeavor, by drawing out first this corner 

 and then that, to again reduce the gelatinous-looking 

 piece to the condition of a thin film, and it will be 

 found that this can be effected without much diffi- 

 culty, for when not floated up by fluid the thin edges 

 of the film tend to stick to the glass, and cease to 

 shrink away from the position to which they are 

 drawn by the needles. At the same time, whilst it 

 is important not to add fluid to that which naturally 

 moistens the piece of tissue, it is equally important 

 never, during the whole process of stretching, to let 

 the film become actually desiccated, for this would 

 altogether ruin the tissue for microscopic purposes. 

 The best way to prevent such an untoward result 

 from happening is to breathe now and then on the 

 object whilst it is being prepared; by so doing need- 

 less haste will be avoided and more time and pains 



