330 EVENINGS AT THE MICROSCOPE. 



To return to the living specimen on the leaf : you see 

 seated in the angles of the branches here and there elegant 

 urn-shaped cells, larger than the polype cells, each with a 

 sort of shoulder and a narrow neck. The common marrow 

 passes from the joint into the bottom of these, and then 

 extends through the centre till it reaches the mouth. In 

 some of the urns this forms merely a slender column, ex- 

 panding at the mouth ; but in others it enlarges at irregular 

 intervals into large knobs or masses of granular flesh, 

 which are confusedly grouped together, eight or ten in one 

 capsule. This latter is the most interesting condition ; let 

 us watch it. 



While doing so, let me inform you that these urns are the 

 reproductive organs, and the fleshy masses are embryos of 

 peculiar character, which are developed out of the nutrient 

 medulla. The largest of those now under observation is, 

 as you see, moving, and slowly working its way out of its 

 glassy prison. Two or three flexible finger-like bodies 

 are protruding from the orifice of the urn, and more 

 are joining them: we see they are tentacles, protruded 

 in a loose bundle, just as the polype emerges from the 

 cell. 



It is a somewhat slow process ; but at length the fleshy 

 mass squeezes itself forth, as if pushed out by some con- 

 tractile force behind ; while we see the fluids, carrying 

 granules, run into the parts of the tentacles which are 

 already free. The embryo is liberated. 



For a few seconds it appears helpless, and falls through 

 the water in a collapsed state, so that we cannot discern 

 its proper form. It gives a spasmodic contraction or two, 

 feeble at first, then more vigorous ; the tentacles lengthen, 

 the body expands, and lo ! it is not a polype, but a 

 Medusa ! 



And now take your eye for a moment from the micro- 

 scope, and glance at this glass jar, in which the oarweed 

 with its colony of Zoophytes has been standing for a few 



