446 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 22, NO. 12 



vulva, together with an associated complicated nerve plexus. This muscula- 

 ture is least developed behind the vulva. 



The straight uterus, 30, 8, extends forward, and is of such capacity as to 

 accommodate a maximum of about forty eggs, 10, 39, (i.e., many more than 

 shown in this drawing) arranged approximately single file, although this 

 large number of eggs is rarely seen except toward autumn. Under such cir- 

 cumstances the oblate eggs, seeming to nearly fill the body cavity in this region. 

 are more or less ellipsoidal in contour and half a body-width long, and twice 

 as wide as long. When deposited, or when not crowded in the uterus, the 

 eggs are ellipsoidal and longer than wide. The shells of the eggs, one and a 

 half microns thick, are smooth, and the eggs are deposited before segmentation 

 begins. Naturally, the length of the uterus varies according to the number 

 of eggs it contains. 



The broad reflexed ovary appears more or less cylindroid, and when there 

 are, say, a dozen eggs in the uterus, the terminus of the ovary, 59, lies about 

 halfway back to the vulva. The narrow oviduct, 46, 52, leading from the 

 front end of the ovary back to the uterus, is usually nearly invisible, but when 

 a ripe ovum, 50, having passed round the bend (flexure) near 46, is being 

 forced backward through it from the front part of the ovary back to the 

 uterus, its presence is obvious. It is faintly visible at 52. The ova are 

 fertilized on first reaching the uterus, and soon after this it is not very un- 

 common to witness the early stages of the formation (mit, Fig. 1) of the polar 

 bodies, which appear later as small spherical bodies just under the eggshell. 

 A small collection of sperms is seen in the spermathecal region at 61. 



The demanian system. In the adult female of Metoncholaimus pristiurus 

 there is a complicated double system of efferent tubes, the demanian vessels, 

 connecting, first, with the posterior part of the intestine through an osmosium, 

 87, and second, with the posterior end of the uterus by means of a very long 

 slender efferent duct, 79, 85. These two efferents join at a conspicuous 

 thirty-two-merous, special glandular gateway, the uvette, 40, and empty, 

 by way of the uvette pore, 62, thence backward and outward through two 

 separate narrow lateral ducts, 42, having attached to them, along their outer 

 sides, relatively large and long conspicuous moniliform affluent glands, 64, 

 seventeen microns wide, each consisting usually of sixy-four somewhat 

 discoid elements, 66, occasionally double (?) this number. These discoid 

 cells of the two moniliform glands are three microns thick and packed with 

 granules of the order of one micron; the flat ducts, along the inside of the 

 moniliform glands, lead to two exit pores, the right hand one shown at 17, five 

 by seven microns, laterad in the body wall one-half tail-length in front of 

 the anus. However, the caudad elements of the moniliform glands are 

 "pyriform," as shown in the illustration, not discoid. The demanian vessels 

 elaborate a copious, elastic, sticky, non-water-soluble, nearly colorless secretion, 

 possibly utilized during agglomeration and copulation, and also mayhap to 

 protect and preserve the batches of eggs after deposition and during seg- 

 mentation. 



The uvette, 40, is a very striking organ consisting of thirty-two concen- 

 trically arranged, highly refractive, flask-shaped, glandular elements, all 

 concentric about a single minute central pore, 62, leading into the large duct 

 passing backward and dividing to form the two lateral efferent ducts each 

 accompanied by a sixty-four-fold moniliform gland, as already described. 

 The connection of the intestine with the demanian system at the osmosium 

 is not an open one; the nature of the connection with the uterus, however, 

 appears less certain. 



