52 COLLEGE ZOOLOGY 



bites. Quinine is the remedy commonly used against the 

 malarial parasite. It acts directly upon the younger stages 

 of the organism, causing their death. 



c. Sporozoa in General 



The SPOROZOA are PROTOZOA without motile organs. They 

 are parasitic in METAZOA. Reproduction is mainly by spore 

 formation. The following classification is simplified from Min- 

 chin's account in Lankester's Treatise on Zoology, Part I. 



SUBCLASS i . TELOSPORIDIA. SPOROZOA in which the life of 

 the individual ends in spore formation. 



Order i. Gregarinida. TELOSPORIDIA possessing a firm 

 pellicle and complex ectosarc; intracellular during the early 

 stages of the life cycle, later free in the body cavities of inverte- 

 brates. Examples: Monocystis (Fig. 32), Porospora, Gr&garina. 



Monocystis (Fig. 32) may be found in the seminal vesicles of 

 almost every earthworm; Gregarina is a common parasite of the 

 cockroach; and Porospora gigantea, which reaches a length of 

 two-thirds of an inch, inhabits the alimentary canal of the lob- 

 ster. 



Order 2. Coccidiidea. TELOSPORIDIA simple in structure; 

 trophozoite is a minute intracellular parasite. Example: Coc- 

 cidium. 



Members of this order are sometimes found in the liver and 

 intestine of man and other vertebrates, and in ARTHROPODA and 

 MOLLUSCA. 



Order 3. Haemosporidia. TELOSPORIDIA parasitic in the 

 blood of vertebrates. Example: Plasmodium (p. 50). 



SUBCLASS 2. NEOSPORIDIA. SPOROZOA which give rise to 

 spores at intervals during active life. 



Order i. Myxosporidia. NEOSPORIDIA with ameboid inter- 

 cellular trophozoite. Example: Nosema. 



The MYXOSPORIDIA are parasitic especially in ARTHROPODA 

 and fish, frequently causing serious epidemics in aquaria. 

 Nosema bombycis produces the silkworm disease, pebrine. 



