Studies in Laboratory Work

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1907 Excerpt: ...in Canada balsam. By this method the developed malarial parasites are not well shown, as they will not stand drying or dehydration without great distortion. The salivary glands can be mounted in the same way, but in the Farrant's solution the cells wrinkle and poor results are obtained. Somewhat better results are obtained by removing extraneous tissues under the microscope and drying the slide in the air. The salivary glands can then be fixed, stained and mounted. In the fresh preparation the cells will be found to vary greatly, and they are often distended with refractile droplets. These may be so numerous as to fill many or all of the cells. The cells in the middle lobe are smaller and often differ in appearance from those in the lateral lobes. The main duct has cubical epithelium, which is continued for some distance down the lobules. In Anopheles the ends of the ducts in the lobules are dilated, whilst in most of the genera the ducts maintain the same calibre in their entire length. Occasionally a diverticulum is met with. This may be terminal, so that the lobule bifurcates at the end, or it may be found in any other part. In Psorofhora each gland has five lobes. At first there may be difficulty in finding these glands with a low power. The point to search for is the main duct and its trifurcation, as this is most readily seen even if the gland is embedded in muscular or other 242 GENITAL ORGANS tissues. To see the character of the glandular cells in detail a ts oil immersion must be used, and the diaphragm nearly closed, as the cells are very transparent. Sporozoa have been described in the ovaries of the mosquito, and we know that the piroplasma of cattle and dogs are transmitted by an infected tick to its offspring. In the present state of our knowl...