54 



The s;('<;ineiils close to the scolex are 

 siuull aud immature, further away 

 they are larger and more developed, 

 at the end of the chain they are ma- 

 ture or ripe. The ripe segments are >• 

 detached from time to time and pass ► 

 into the contents of the intestinal ^ 

 car.al and escape from the body g 

 with the faeces. These mature seg- ^ 

 raents are provided with contractile ^ 

 fibres in their walls and are able to % 

 move about. They contain eggs. "C 

 Their- life outside of the animal in & 

 which they are developed is short, and s 

 when they die and break open the | 

 eggs escape. If these fall in a damp 2 

 place, thev retain their vitalitv and c 

 power to mature for a long time, in | 

 some cases many months. | 



A remarkable and interesting fact^l 

 in connection with the life historv of I 

 the tapeworm is that the eggs will not 

 develop into mature worms in the 

 body O'f an animal belonging to the 

 species of the one in which they were 

 produced. It is necessary that they should first enter 

 the body of an animal of a different species and there 

 develop into embryos, whicli ])ass through the walls 

 of the intestinal canal and j)enetrate to distant parts 

 of the body. There the embryos remain in a some- 

 what more advanced state of development until their 

 host dies and is consumed by an animal belonging to 

 th(^ species of the original host. 



This can be illustrated bv brief! v describing the life 



