MICHIGAN ACADEMY OF SCIENCE. 73 



Budding. A form of unequal fission known as "Knos})cnbildung" has 

 been observed by Swarczewsky (08) and others. The first indication 

 of this process is the disintegration of the nuclei into fragments which 

 are distributed throughout the body plasm toward the periphery of the 

 animal. These particles are recognized as "bud-nuclei" of characteristic 

 appearance. Now a portion of the protoplasm differentiates itself by 

 becoming denser and more refractive. This portion, containing a bud- 

 nucleus, separates from the parent and passes out of the shell in amoeboid 

 form. After sinking to the substratum, it develops an investing mem- 

 brane, undergoes a resting period, and finally develops directly into a 

 normal individual. 



"Agamoganie." A related phenomenon is that referred to by Elpatiew- 

 sky ('07) under the name Pseudopodiosporenbildung. The amoeboid 

 spores arise in the same manner practically, and emerge from the shell 

 one after another. After creeping about the opening of the shell for a 

 considerable period, they assume a helipzooid form with radiate pseudo- 

 podia and vacuolated structure. Such forms have often been observed 

 in cultures, and have been assigned to various places in the order. 



Swarczewsky's observations ('08) have not been in entire accord with 

 these. He declares that the "agametes" leave the shell immediately. Five 

 were described as leaving at one time, followed in five minutes by two 

 more. I have never seen more than one or two such structures at a time, 

 and only seldom. The phenomenon is said under certain conditions to be 

 found in all the individuals of a culture. Occasionally the whole mass 

 of protoplasm may desert the shell and wander almost in irregular 

 amoeboid shape, giving off numbers of these smaller forms. 



Sporulation. The formation of two kinds of gametes, which conjugate 

 and later form a resting stage which subsequently develop into adult 

 forms, has been described by many authors. Ill understood as this 

 phenomenon is, it seems to be one of the customary methods of reproduc- 

 tion in many of the Protozoa. The adult body breaks up into nucleated 

 fragments of one of two kinds. These "micro" and "macro-amoeben ' 

 emerge from the shell and progress by means of short, broad pseudopodia. 

 Finally they become symmetrically radiate, and copulation occurs be- 

 tween the two forms. The subsequent history is probably the develop- 

 ment of a cyst, and final production of a shelled form. 



Plasmogamie and Conjugation. Often normal fission is interrupted by 

 what generally passes for conjugation. Two individuals of the same 

 appearance are applied face to face, with the body protoplasm united, 

 while a slow mingling of materials occurs. I have endeavored to follow 

 this process through in many cases which I have observed but have never 

 been able to find any definite results. After long union the individuals 



