remains on the posterior end of the larva (Fig. 255) which is quickly 

 smoothed. The development of the internal organs proceeds slowly with 

 the exception of the intestine. Already in the larva which has 2-3 pairs 

 of clamps the latter forms 2 lobes extending into the posterior end of the 

 body (Fig. 256). These grow very quickly and change into the intestinal 

 trunks of the adult form. The sex system is developed considerably 

 later. Approximately at the stage which has 13 to 16 pairs of attaching 

 clamps one can observe the sex armature and considerable development 

 of the sex glandsj whereas among individuals with 8 pairs of attaching 

 clamps the sex system has not yet been fully differentiated. 



Microcotyle donavini Beileden and Hesse --In her resume" 

 Sproston indicates a rather early stage of the development of this type with 

 only 12 pairs of clamps. The given stage of development still has middle 

 hooks at the end of the disc which are absent in subsequent stages. Thus, 

 the falling -off of the cercomere in the given species takes place during 

 relatively late stages. 



p. 214 



28. The development of Axine Abildgaard 



The genus Axine (Fig. 8) is close to Microcotyle but differs by 

 an asymmetrical disc located obliquely in relation to the longitudinal axis 

 of the body. The preservation of the larval middle hooks lying in the 

 middle of the single longitudinal row of attaching clamps is characteristic 



€lMM 



"X. 



OMIum 



-— <3^ 



Fig. 258. Axine belones Abilgaard, 

 attaching armature of the free- 

 swimming larva. 



Fig. 257. Axtne belones- Abildgaard free- 

 swimming larva. (Drawing from the pre- 

 paration by U. A. Strelkov). 



for the adult form. 



233 



