Anatomical structure of Aspidogaster conchîcola. 501 



extending into the parenchyma in a direction slanting backwards and 

 outwards towards the surface. Some of these stretch to a greater 

 distance than others and have consequently long discharging ducts all 

 of which however lie parallel and closely packed together and open 

 into the mouth funnel just in front of the pharynx (prepharynx). 



VoELTZKOW has given a fairly accurate drawing of these glands 

 which he names "Speicheldrüsen" taking them to be analogous to 

 glands of this designation in other genera, but which open into the 

 intestine posterior to the pharynx. 



In the parenchyma of the foot occur also similar glands (Fig. 2, 

 7 G) — foot glands, infraseptal glands. They are seen to ad- 

 vantage when the worms are cleaving to a watch glass or object glass un- 

 covered, or under a loosely applied glass slip supported on wax feet. 

 Very often one can be found with ventral sucker pressed tightly on 

 the glass and spread out past the sides of its body and far in front. 

 Also where the worm is fastened on coverslip instead of object glass, 

 or when it is found swimming on the surface of the fluid — in both 

 cases with sucker upwards — advantage may be taken to observe 

 the natural position of these glands. They are tubes of various 

 lengths lying in the infra-septal parenchyma entirely above the limiting 

 membrane of the ventral sucker. The course of those lying most 

 anteriorly is pretty nearly straight towards the front end of the foot, 

 while those belonging to the sides extend forwards, outwards and 

 downwards. Often they are arranged in little groups of two, three 

 or several together and all of one group having the same course, but 

 they may be more or less bent to and from one another. In order 

 to trace them to their termini and to see their structure more clearly 

 one must of course use high powers which also occasions the com- 

 pressing of the animal to make it thin enough. To gain this ad- 

 vantage one looses that of seeing the glands in their natural position. 

 The foot comes to be compressed under other parts of the body which 

 must be shoved over to one side. It is not often that the animal is 

 found symmetrically compressed dorso-ventrally, and when it is so 

 obtained it is still too thick to be of much advantage. I have in 

 some preparations found regularly occurring cloudy patches of secretion 

 substance which had been squeezed out of these glands. These were 

 distributed at intervals along the side of the sucker and indicated 

 where the mouths of these groups of glands were to be found. In 

 living animals as well as from sections I have satisfied myself that 

 they open pretty generally near the line where the limiting membrane 



