168 SOME FRAGMENTS OF WEED 



water to seek a new resting-place and begin life on its own 

 account. 



Baker relates an interesting fact in regard to the voracity of 

 the hydra, which it may not be out of place to quote. He says : 

 — "Sometimes it happens that two polyps will seize upon the 

 same worm, when a struggle for the prey ensues, in which the 

 strongest, of course, gains the victory, or each polype begins 

 quietly to swallow his portion, and continues to gulp down his half 

 until the mouths of the pair approach and come at last into actual 

 conflict." They then wait till the worm breaks in two, " when 

 each obtains his share ; but should the prey prove too tough, woe 

 to the unready ! The more resolute dilates its mouth to the 

 requisite extent, and deliberately swallows its opponent, some- 

 times partially, so as, however, to compel the discharge of the 

 bait, while at other times the weaker hydra is engulphed. But a 

 polype is no fitting food for a polype, and his capacity of endur- 

 ance saves him from the living tomb, for after a time, when the 

 worm is sucked out of him, the sufferer is disgorged with no other 

 loss than his dinner." 



Melicerta ringens is one of the Rotifera, and is esteemed a 

 great prize amongst most microscopists on account of the ingenu- 

 ous way in which it constructs the tube it inhabits. This marvel- 

 lous creature builds his mansion brick by brick, making his 

 bricks as he goes on, from substances floating around him, and 

 shaping them in the mould which he carries upon his body. 



Looking at this strange creature under the microscope, we 

 observe a tower composed of light, reddish-brown pellets ; then 

 suddenly from the top protrudes a complicated mass of trans- 

 parent flesh, which slowly expands, disclosing two large, rounded 

 discs, around which a wreath of cilia is seen in active motion. 

 This is followed by two smaller leaflets, likewise surrounded with 

 cilia. Between the lower leaves the gizzard is seen grinding away, 

 and above it is an organ of which the eminent naturalist, Mr. 

 Gosse, was the first to discover the use. This organ resembles 

 the circular ventilators sometimes seen in kitchen-windows, and 

 Mr. Gosse found that it was the machine for making the bricks of 

 which the creature constructs its house. In order to obtain the 

 materials for brick-making, the builder modifies the direction of 



