180 Specific Examples of Slide Making 



Therefore, at about an inch on each side of the center of a glass slide 

 is placed a thick No. 3 coverslip, which may be held in place by the 

 capillary attraction of a drop of water. The specimen is picked up from 

 the water with a large eye-dropper type of pipette and placed in a large 

 volume of water on the slide. It is then easy to arrange the parts with 

 needles, but it is difficult to lower a second slide without disarranging 

 these parts. An alternative method is to place the slide with its coverslips 

 in the finger bowl with the specimen, to arrange its parts under water, and 

 to place the second slide on top. Whichever process is adopted, the slides 

 are tied or clipped together and transferred to a jar of 96 per cent alcohol, 

 where they may remain for a week or until next required. Each specimen 

 is treated in this manner. It is better not to try to flatten two or three 

 specimens on one slide. 



When it is time to continue mounting the specimens, the slides are 

 placed in a finger bowl of 96 per cent alcohol before cutting the cords or 

 removing the clips that bind them together. Getting the two slides apart 

 without damaging the specimen is not easy, particularly if the specimen 

 tends to stick to one or the other of the slides. The simplest method is to 

 insert the blade of a scalpel into the gap between the slides and twist it 

 slightly to see whether or not the specimen is free. If the specimen shows 

 signs of sticking to one slide, the other may be removed, and the specimen 

 washed from the slide to which it is stuck with a jet of 96 per cent 

 alcohol from a pipette. If it shows signs of sticking to both slides, it is 

 still possible to free it from both by projecting a jet of 96 per cent alcohol 

 between them. Each slide is treated in due order until one has accumulated 

 all the flattened specimens in a dish of 96 per cent alcohol. It must be 

 understood that these specimens have been hardened flat, so that no 

 amount of subsequent treatment will ever swell them out again or prevent 

 them from remaining in the required position. 



It is recommended, if there are several specimens to be handled, that a 

 series of the little cloth-ended tubes shown in Fig. 80 be used. The only 

 alternative is to handle each specimen with the aid of a section lifter, 

 with the consequent risk of damage. Although not nearly so satisfactory, 

 it is also possible, at least for the process of staining and dehydration, to 

 place all the specimens in a small vial in which the different fluids used 

 may be placed successively. 



A wholemount of this type is best stained in carmine, and the choice 

 would lie between Mayer's carmalum and Grenacher's alcoholic borax 

 carmine; the author's preference is for the latter. The preparation of the 

 latter stain, the formula for which is given in Chapter 7, does not present 

 any difficulty, but it should be noted that a differentiating solution of 0.1 

 per cent hydrochloric acid in 70 per cent alcohol will be required. Ade- 

 quate supplies of this should be available before one starts staining. 



The specimens are now passed from 96 per cent alcohol to 70 per cent 



