664 DESCRIPTION OF T^NIA MADAGASCARIENSIS. 



objects the embryonic hooks appear in the form of fine rods. Regarding 

 the structure of the head and the anterior part ef the body unfortunately 

 nothing is known. The smallest joints hitherto observed had a breadth 

 of 2'2, and a length of 0*8 mm. 



We owe the discovery of this worm to Dr. Grenet, head of the 

 French Medical Department in Mayotte, an island on the coast of 

 Madagascar, who expelled it by means of castor-oil from a boy of six- 

 teen months old, and also from a girl two years of age, who had settled 

 in the island only two months before. In both cases the children 

 were suddenly and without any assignable cause attacked with con- 

 vulsions, which ceased after the use of the anthelminthic. The first 

 patient voided, in consequence of the latter, no fewer than nine, and 

 the other two worms, which unfortunately have only reached Europe 

 in fragments. The largest of these, which was given to Davaine for 

 investigation, contained seventy-five segments. Two other shorter 

 ones exhibited seventeen and eighteen ; and there were further three 

 pieces with two joints each. All of these originated from the first 

 of the two young patients, while from the second there was only 

 received one chain with fifteen ripe proglottides. According to 

 Grenet, the latter possess, in their isolated state, great contractility, 

 and crawl about nimbly upon the faeces, with pronounced changes 

 of form. 



What Davaine has communicated regarding the reproductive 

 organs of this species shows that, except as regards the egg-capsules, 

 they essentially correspond with the ordinary forms. The most 

 anterior segments exhibit no recognisable reproductive organs, being as 

 yet sexually undifferentiated (" neutre") ; and the succeeding ones have 

 at first their male organs chiefly developed. The vas deferens and 

 penis could be distinctly observed. The letter is described as a smooth, 

 short, and somewhat stout cylinder (with a diameter of 0*025 mm.) 

 protruding as much as 0'04 mm. out of an opening situated in the 

 centre of one of the lateral borders. The vagina, whose course can be 

 distinctly followed, also terminates as usual in this opening. As we 

 have already mentioned, in giving the characters of the group, the 

 pores are all found on the same lateral border. 



The feature which is most characteristic of this worm, and which 

 obviates any doubt as to its specific nature, is, as we also previously 

 observed, the structure and nature of the egg-balls. To the naked 

 eye the latter appear in the form of small points, which become 

 visible as soon as the proglottides are 1 mm. in length. From the 

 structure which they exhibit when placed under the microscope, Grenet 

 has compared them to the cocoons of the leech. Since we have learned 



