HYDRA. 191 
4, Hypra OLIGACTIS. 
Hab. Still waters, in England, rare; Hackney, Ellicot ; 
Cranmore, near Belfast, Templeton. 
“The tails of these are long, slender, and transparent, and 
when placed before the microscope, a long straight gut may 
plainly be distinguished passing from the body-part or 
stomach, to an opening at the end thereof. These are rather 
lighter-coloured than the former (H. vulgaris), and have 
seldom more than six or eight arms, but these capable of 
great extension.” (Baker.) 
Dr. Fleming regards the above-mentioned species as 
varieties of Hydra vulgaris; he remarks, “The reproduction 
of this singular being by buds issuing from the sides of the 
parent polype; acquiring tentacula, and then falling off and 
becoming independent individuals, or by the regeneration 
of parts when artificially divided ; has long engaged the at- 
tention of the curious observer. The animals may be easily 
procured by placing a quantity of the stems of plants grow- 
ing under water in any slow-running ditch, in a basin of 
clean water, and in a short time the polypes will expand, and 
exhibit themselves readily to the naked eye.” And yet how 
few have tried to see them! 
