MICROSCOPIC WONDERS 21 



One of the largest of the Ciliata is Paramecium. It is just 

 visible to the naked eye, as a minute white speck. 



Like many others of the Protozoa, it is able to change its 

 shape when occasion needs, but it does so only temporarily, 

 for it very soon regains its usual form when it has passed the 

 obstacle. Its body is covered with short, hair-like cilia, which 

 it uses in swimming. Its mouth, known as the vestibule, is 

 a cone-shaped depression, furnished with long cilia, by means 

 of which very minute particles of organic matter are washed 

 in. When Paramecium is interfered with or wishes to obtain 

 living food, it shoots out long threads, from certain special 

 organs known as " trichocysts." These threads, in some way 

 or other, have a paralysing effect upon the victim. 



Multiplication occurs by conjugation. Two individuals 

 fasten together, and their protoplasm becomes continuous 

 through their mouths. The nuclei then undergo changes, 

 after which the creatures separate. And curiously enough, no 

 sooner has this occurred than both Paramecium divide into 

 two, thereby forming four young ones of the same kind. 



Paramecium is popularly known as the Slipper Animalcule, 

 because it to some extent resembles such an article. A bed- 

 room slipper, that has seen much wear, and is thereby out of 

 shape, is perhaps rather like the creature. 



Trachclocerca Olor, or the Swan Animalcule, is one of the 

 most charming of all the Protozoa to be found in a pond. 



Its title it certainly well deserves, for it has the extra- 

 ordinary power of forming a swan-like neck of surprising 

 flexity when required, or I might better say of reducing its 

 neck to a short, stumpy growth when occasion needs. 



At times it will rest in one spot, its neck writhing so grace- 

 fully that it reminds one of the artistic arm play of the well- 

 known Maud Allan style of dancing, except that the minute 

 creature is the essence of gracefulness, each movement rounded 

 off with a perfectness that the dancer can never attain. 



And if we have the opportunity of watching this minute 

 animal at play, gracefully twisting its neck into all sorts of 

 inconceivable evolutions, we begin to wonder if there is any- 

 thing new in this world of ours. 



It is hard to describe the movement of that neck, so supple, 

 and so lithe, that one expects any moment that it will break 

 with the effort to form the necessary curve, and when Trach- 

 clocerca Olor becomes active in search of food one realises the 

 value of the play. We are all aware that unless in practice 

 we soon become unfit, and to be an expert at rapid and yet 

 comfortable movement every muscle must be exercised. And 



