THE CUCUMBER AND TOMATO EELWORM. 53 



The roots of plants when infested with Root eelworm present 

 an irregular, knotty, or warty appearance, and are often from two 

 to ten times larger in diameter than ordinary roots. These nodu- 

 lar enlargements or root galls when first formed are smooth and 

 light in colour, but at a later date the surface roughens and cracks, 

 and is then dark brown, owing to the root gall having commenced 

 to decay. 



If we take one of these brown decaying galls and pull it care- 

 fully apart, we may probably see with the naked eye small white 

 oval bodies lying in the darkened decaying tissues. These more 

 or less oval bodies are the matured female cysts (PI. VI., Fig. i), 

 being from one-fiftieth to one-hundredth of an inch in diameter. 

 They are pointed at the head end, and under the microscope the 

 cyst or chamber looks like an inflated bladder, or what Professor 

 x^tkinson calls "a crooked-necked squash.'^ 



In the head end we find a mouth (Fig. i, «), provided with a 

 hollow exsertile spear (Fig. 2). This spear is found in both sexes, 

 and can be extended with considerable force, its use being (i) to 

 batter in the cell-walls of the plant, either to enter or exit ; and (2) 

 to form a passage by which the food may be drawn into the 

 stomach of the worm. The food passage looks, when viewed 

 under the microscope, like a dark fine running down the centre of 

 the spear, which terminates in an egg-shaped muscular gizzard or 

 stomach (Fig. i, ^), the latter being attached to the alimentary 

 canal. 



If we look carefully at one of these female cysts under the 

 microscope, we may be able to see lying in its interior two long 

 coiled cylindrical objects having free ends (Fig. i). These are the 

 genital tubes, and in a fully developed cyst will be found to be 

 packed with eggs in all stages of development. The eggs are 

 developed in immense numbers in the ovaries (Fig. 1, c), and as 

 they increase in size they pass along the oviduct (Fig. i, d), and 

 are finally expelled from the vulva (Fig. i, e). When the eggs are 

 expelled they are cylindrical in shape, but they soon change in 

 form, ultimately becoming bean-shaped (Fig. 3). The eggs are 

 from three to four-thousandth part of an inch in diameter. 



The eggs are filled with protoplasm, in which may be found a 

 nucleus (Fig. 3, n). The early process of development of the egg 



