THE HYDRA. 27 



5. Their three methods of reproduction : 



(a) By buds. These are blunt processes often seen 

 sticking out at right angles to the body of the parent 

 hydra, outgrowths from its sides, destined to become perfect 

 hydras, and, when well grown, to separate, and lead an 

 independent existence. All stages of the budding process 

 may usually be found, from the incipient bud without 

 tentacles, to the fully formed hydra ready to drop away. 



(5) By true sexual organs, minute cone-shaped or 

 dome-shaped eminences on the sides of the body, just 

 visible without a lens. 



(c) By a sort of vegetative reproduction, like the starting 

 of a new plant from a slip or cutting taken from an old 

 one. To see this will require a carefully conducted exper- 

 iment, costing a little time and trouble, but worth both. 

 Cut out a piece of leaf with three hydras on it, and place 

 it and them in a separate vessel of water. With a pair 

 of thin, sharp scissors, cut off a tentacle from one of the 

 hydras, to see it reproduced. Cut the second hydra in two 

 crosswise, and slit the third one into two pieces length- 

 wise. If properly done, the pieces will live, and each 

 will develop into a perfect hydra. The progress of these 

 specimens should be watched daily, and as much oftener 

 as is convenient. 



Detach a hydra from its support, take it up with a 

 dropping tube, and place it in a watch crystal containing 

 water under the microscope, and examine with low power. 

 Observe : 



1. The broad or flattened foot by which it was attached. 



2. The flexible cylindrical body (often distended in 

 places by food, or extended into buds). 



3. The tentacles: their number; their knotted appear- 

 ance ; their action. 



4. The cone-shaped prominence (hypostome) at the 

 anterior end, between the bases of the tentacles. 



