METAMOEPHOSES OF TRICHODA LYNCEUS. 



53 



(110.) The remarkable history of Trichoda Lynceus has been studied 

 by M. Jules Haime*. This animalcule would appear to commence its 

 existence under the aspect of an Oxytricha (Ehrenberg) (fig. 22,1,2), in 



Fig. 22. 



Metamorphoses of Trichoda Lynceus. 1. Larval condition (Oxytricha), seen from below. 2. The 

 same, after swallowing another animalcule. 3. A very large specimen just about to undergo fission. 

 4. The same, showing the fissiparous process in a more advanced stage. 5. One of the products 

 of such fission. 6. The same, having lost most of its cilia and assumed a spherical shape. 8. The 

 same, now become completely motionless. 9. Appearance of the same after the lapse of fifteen 

 days. 10. Later condition of the same, showing the formation of a cyst. 7 & 11. After the 

 expulsion of a considerable quantity of exuvial matter, a ciliated animalcule appears in the inte- 

 rior of the cyst. 12 & 13. The included animalcule escapes from its encystment and at length 

 assumes the form of an Aspidisc-us, represented at 14. 15. The complete animalcule walking by 

 means of its setae. 16. Inferior aspect of the same when at rest. All the figures are magnified 

 355 diameters, except the two last, which are shown under a magnifying power of 760 diameters. 



which condition it undergoes multiplication by transverse fissure in the 

 usual manner (3, 4). The halves resulting from this division then as- 

 sume a globular form, lose the greater part of their locomotive apparatus, 

 and become encysted (5, 6). The contents of the cyst next separate 

 from their envelope, leaving a space on one side, in which ciliary move- 

 ment can be distinguished (7). This space spreads all round ; granular 

 matter is expelled from the cyst, whereby its form becomes altered (8), 

 and the distinction between the newly formed animalcule to which the 

 cilia belong and the remains of the original creature becomes more and 

 more apparent (9, 10, 11), until at last the former escapes through the 



* Ann. des Sc. Nat, ser. 3. t. xix. p. 109. 



