508 Universittj of California Piihlicaiions in Zoology [Vol.20 



(Yoshida, 1918). Wilson (1916) described pores in the cyst wall of 

 the soil amoeba and observed the process of an amoeba emerging from 

 the cyst through one of these pores. Kofoid and Swezy (1921) 

 recorded the process of budding for CouncUmania lafleuri. By this 

 process a small amount of cytoplasm, together with a single nucleas, 

 emerges through a pore in the cyst wall, and the cytoplasm containing 

 the nucleus breaks off forming a small amoebula. This process is 

 repeated until the cyst is emptied of its contents. If pores are easily 

 demonstrable in cysts of soil amoebae, it seems likely that they may 

 occur in other amoebae. 



The present investigation of the amoebae of rats and mice was just 

 being started at the time the observations on budding in C. lafleuri 

 were recorded. Many similarities were noticed between C. lafleuri and 

 the amoebae of the rat and mouse. These, together with certain 

 figures by Wenyon (1907, pi. 10, figs. 12, 13, 18, 20, 21), though 

 explained by him in a different manner, led to the thought that bud- 

 ding would probably be found in Counrilmania of rats and mice. The 

 assumption was easily verified by observation in the first few animals 

 examined and numerous instances of the process have since been 

 recorded. In C. muris, chromophile ridges and also chromatoidal 

 bodies are common, and observations to date indicate that the budding 

 process occurs in a manner similar to that in which it occurs in 

 C. lafleuri (Kofoid and Swezy, 1921). 



Evidence for this process is based on the following observations: 



1. Buds have been seen in fresh smears prepared in iodine-eo.sin 

 and normal saline, without pressure or other mechanical disturbance 

 having been brought to bear on the cysts. 



2. Buds have been seen in slides permanently stained with iron- 

 haematoxylin. These cysts contain varying numbers of nuclei, indi- 

 cating that some of the nuclei have passed out in previously formed 

 buds. In plate 45, figure 26, the whole eight nuclei are present, one 

 having passed into the bud ; plate 44, figure 28, shows a cyst with six 

 niiclei, one in the bud, and figure 22 of the same plate shoA\s four 

 nuclei in the cj'st, and one in the bud. It further shows light patches 

 in the cytoplasm, indicating spaces from which the nuclei and their 

 surrounding protoplasm have emerged. 



3. Small amoebulae about the size of buds are often found in 

 proximity to the cysts (pi. 45, fig. 22), indicating that they have 

 previously emerged from the cyst. 



