3540 



THE LOWEST ANIMALS 



divide up into spores. Noctiluca is found only in" waters near land, the related forms 

 met with in the open ocean belonging to the genus Pyrocystis. In one of the species 



of the latter the body is spherical, about one- 

 thirtieth of an inch in diameter, and without 

 the big flagellum. The phosphorescence, 

 which in each individual chiefly emanates 

 from the nucleus, is displayed on the ocean 

 surface on calm nights in the Tropics. Pro- 

 fessor Butschli regards this species as an 

 encysted or resting phase of the common 

 form. Noctiluca occasionally swarms in 

 such abundance as to give in daytime 

 a reddish or yellowish hue to the surface. 

 When the sea is rough, the organisms 

 are dashed below the surface, and do not 

 form a sufficiently continuous layer to 

 give rise to much luminosity, and when 

 the wind is off shore they are blown out 

 to sea. 



Among the Flagellata are included cer- 

 tain parasitic organisms, 

 which, owing to their 

 being immersed in nutrient 

 fluids, are not com- 

 pelled to seek further for 

 food, and do not possess 

 flagella. The Gregarina, 

 living in the intestine of 

 the lobster, is an elongated 

 worm-like organism about 

 two-thirds of an inch in 

 length; it multiplies by be- 

 coming a spherical cyst, 

 the contents of which 

 break up into minute spore- 

 like bodies with spindle-shaped cases, which are set free on the 

 bursting of the cyst. Each of the spore bodies also ruptures 

 and liberates an amoeba-like organism, which ultimately de- 

 velops into an adult gregarina. Another species of gregarina 

 lives in the intestines of the earthworm. The Sporozoa are 

 oval or spherical monad-like bodies, but without flagella, and 

 live as parasites in the cells of plants and animals. Cancer 

 and certain forms of malaria have been attributed to the NODDING ^^ ANI ' 



r - , . ,, . MALCULE, EplS- 



presence of organisms of this nature in the fluids and tissues ^,/^ (natural 

 of the body. size = ^ inch). 



BEI.I, ANIMAI,CUI,E ( Vorti cello) . 



a. Slightly magnified ; b. Magnified 600 diameters 

 n. Nucleus ; m. Muscle band. 



