

Parasitic Protozoa. 163 



a more or less uniform shape while in the Gynomyxa the 

 amoeboid phase predominates and the protoplasm of the 

 cell is naked. Belonging to this Gynomyxa is a form known 

 as the Protomyxa A urantiaca discovered by Haeckei on some 

 Spiiula shells off the Canary Islands. In this form the dif- 

 ferent life phases can be observed. They are the large 

 amoeboid plasmodium, voracious and active which in a 

 short time surrounds itself with a cell wall. This then be- 

 comes segmented and spores result which are covered by a 

 sort of chitinous coat, and are in consequence called chla- 

 mydospores. The coat of these soon ruptures and a flagellula 

 escapes that is an organism possessing a protoplasmic ex- 

 tension in the form of a flagellum. This gradually being 

 converted into an amoeba, several of which run together 

 to form the original plasmodium. So here five stages can be 

 recognized, a plasmodium, cyst, chlamydospore, flagellula, 

 and Amoeba. This gives the series of life phases through 

 which a simple form passes and they can be watched with 

 comparative ease under the microscope. Belonging to the 

 cortk-ata is a large group the members of which pass through 

 a similar series ef stages and which are parasitic. The group 

 is known as the Sporozoa. They infest the cells of the 

 alimentary tract principally, of nearly every form of animal, 

 insects, lobsters, frogs, rabbits, etc. The life history of 

 them is as follows: A chlamydospore gives rise to one or 

 more flagellula which in the stage invade the cell of the 

 host. Here it gradually increases in size and becomes 

 amoeboid or Englenoid in form having a differentiated 

 cell wall and nucleus and of a more or less definite shape. 

 This seems to be the mature condition, soon two of these 

 fuse together and this is followed by encystment and then 

 sporulation. The spores, after receiving their chitin-like 

 coat, are known as chlamydospores, thus completing the 

 life cycle. Several forms of these Gregarinidae or Sporozoa 

 are now known and their analogy to the stages of the Pro- 

 teomyxa aurantiaca is obvious. One of this group, the 

 Drepanidium ranarum is parasitic on the frog, and the fla- 

 gellula or falciform stage is passed in the red blood cor- 



