VEGETATION OE SEA-WEEDS. 27 



may mention tliat once a fortnight I ponr off the water and 

 give a fresh supply from the sea."^ 



* As my object is to aid in rendering my young friends not merely Algolo- 

 gists, but diligent observers of the phenomena of nature, I shall not consider 

 myself bound to adhere rigidly to one department of nature's works. To 

 encourage them in their researches, I may mention that a single tumbler of 

 water will furnish a rich field for their bright young eyes. This very tumbler 

 which showed me the germination of Algse from seed, and which exhibited 

 also the beautiful Vorticellce, contained numberless infusoria of many kinds, 

 merrily dancing in all directions, and showing that he who made them, blessed 

 them with happiness. These animalculites I had seen before, but in watching 

 their sportive gyrations, I was gratified with appearances that I had never before 

 observed. Pei-ceiving what I thought a little hazy spot on the glass, I applied a 

 lens, and found that it did not adhere to the glass, but was moving up and down. 

 Afterwards more than a score were observed, some of them little semi-pel- 

 lucid, and, I think, hollow balls; — others more like broad flattened bonnets, 

 such as are worn at times by carriers ; — with an aperture for the reception of 

 the head. The largest, however, were less than a line in diameter, and of a 

 light grey colour. When the tumbler was allowed to remain unmoved, they 

 lay invisible at the bottom ; but when it was gently agitated, they mounted 

 up like little balloons to the surface of the water, and then gradually descended. 

 How they moved I could not tell. The sm-face of the balls in certain lights 

 seemed a little hirsute, but I could observe nothing like the motion of cilia. 

 When they were all in motion, some ascending and others descending, the 

 mystic movements of these little spheres presented a very animated spectacle. 



But what were my little peripatetic puff-balls ? At first I despaired of being 

 able to tell ; but fortunately I had beside me Sir J. G. Dalyell's recent publi- 

 cation, and turning over its pages and plates I was delighted to find that 

 what I had contemplated with so much interest was the progeny of Bledusa^ 



