50 Dr. H. Krabbe on the Cestoid Worms of the Bustard, 



upon one side or the other, in which especially the ova were 

 collected, 



A single younger specimen, of a little more than 10 millims. 

 in length, in which there was not yet any trace of generative 

 organs, furnished some elucidation of the mode of develop- 

 ment of the joints. The anterior extremity of the worm pre- 

 sented the same characters as in the more developed speci- 

 mens ; it had exactly the same appearance, and was only a 

 little smaller ; but behind it the breadth diminished, so that 

 the whole of the posterior region was very small, only 0*1 

 millim. broad, although already distinctly and throughout 

 quite regularly divided into joints, the number of which 

 amounted to about 110. Now, considering that the number 

 of joints in the more developed worms was smaller in propor- 

 tion as the development of the sexual apparatus and therewith 

 the enlargement of the joints had advanced forwards, it would 

 seem certain that the formation of all the joints takes place 

 before the sexual organs begin their development, and that 

 their development subsequently advances from behind for- 

 wards, whilst the posterior joints are successively thrown off 

 as they reach maturity. 



As this tapeworm cannot be referred to any known genus, 

 I will propose to call it Idiogenes Otidis. I assume that the 

 anterior region furnished with finger-like processes may be 

 regarded as the head or scolex. The ova exactly resemble 

 those which occur in several species of Tcenia] but the 

 mode of development of the joints differs from the usual 

 mode. 



If we examine Bremser's fig. 13, and Nitzsch's figs. 2, 3, 5, 

 and 6, as cited, in which joints of T. viUosa with protruded 

 sexual organs and more or less distinct indications of the internal 

 sexual apparatus are represented, the supposition will be forced 

 upon us that a confusion of this tapeworm with Idiogenes Otidis 

 may have taken place ; and, with regard to Bremser's figure, 

 it appears to me very probable that it belongs to Idiogenes. 

 With regard to Nitzsch's figures, it might in such case be 

 assumed that the generative apparatus of Idiogenes was drawn 

 in the joint of T. viUosa; at least I have never met Avitli 

 joints of T. viUosa with sexual apparatus of this appearance. 

 It is possible that Nitzsch might have been misled by Brem- 

 ser's figure, and sought, by his somewhat diagrammatic figures, 

 to bring about an agreement : and with regard to this, it may 

 be remarked that it is diilicult to obtain a complete and cohe- 

 rent specimen of T. viUosa, in consequence of the interknotting 

 which has already been referred to, and the facility with which 

 they are broken up into fragments. 



