BY W. R. COLLEDGE. 55 



muscular rings, and gradually expands as it enters the stomach. 

 This is a very expaasible muscular bag, swelling out to a con- 

 siderable size after a good meal of blood. It may be dissected 

 into five coats. The outer consists of a network of trackeal or air 

 tubes, below this are two coats of muscular fibres crossing each 

 other at right angles. Then comes a thin structureless mem- 

 brane, and lastly the lining membrane of the organ. From the 

 lower portion of the stomach five blind tubes arise, they look 

 as if they had been grafted on the organ ; they rise parallel to 

 the sides, then bending backwards, curl about the lower part of 

 the abdomen, the outer end of each tube lying free in the cavity 

 of the body. They are called the malpighian tubes, and are 

 supposed to exercise functions similar to the liver. They appear 

 to be divided into angular partitions, and large circular cells of a 

 glandular nature dot their walls at regular intervals. A little 

 lower on the screen lies the intestine. It is attached to the last 

 segment of the body, showing the two terminal hooks. The 

 whole of the organs of the abdomen are subject to a perisaltic 

 motion ; they are drawn upwards towards the chest, and then 

 thrust downwards with a regular rhythmic movement every few 

 S3Conds. In the downward act, the muscular walls of the large 

 intestine roll in concentric waves and force the contents 

 onwards, and in the upward act the contents return to the end of 

 the section in which they lie. There is thus a continual move- 

 ment of the contents of the intestines, exposing them thoroughly 

 to the digestive fluids. 



This is the interior of a female, and these two large pro- 

 jections on each side are the egg sacs. In the unimpregnated 

 state they are made up of clear globular cells, each with a 

 nucleus not unlike two masses of colourless grapes. A big air- 

 tubi passes over the upper portion, giving off branches, which 

 ramify not only over, but right through the egg mass. From 

 one end of each sac, a tube leads to the lower orifice of the body, 

 and when the eggs are ripe they pass down singly and are con- 

 veyed to the outside, being placed into position by the terminal 

 hooks on the body. At the lowest point of the slide is seen 

 what appears to be one of the renal capsules. It is an oval 

 brown vesicle. 



The parasites of Malarial fever have received a large amount 

 of attention. Successive observers in various countries have 

 been gathering up facts, and their life history is being steadily 

 unravelled. Drs. Manson and Ross state that blood drawn from 

 a malarial patient has a peculiar character. A large number of 



