Mr. H. J. Carter on Ramulina parasitica. 97 



colourless into an opaque, brown, dust-like mass, consisting 

 of the spherical spores just described grouped together into 

 variously shaped compartments constructed by flocculent 

 septa, while in other forms, e. g. Stemonites &c., portions 

 of the Plasmodium are thrown up into stipitate heads (spo- 

 rangia of exquisite form and structure according to the 

 species) whose contents undergo similar changes to those 

 of the y^thalium just mentioned ; in short the plasmodium 

 becomes transformed into the adult form of the species, 

 whatever that may be ; this bursts, and the spores becoming 

 free follow the same process in germination as that above 

 described, whereby the life-history of the Mycetozoan is 

 completed. 



Directing our attention next to the freshwater naked and 

 testaceous Rhizopoda, which, through the Gromiids, such as 

 Gromia fluviatilis^ Duj.*, are most intimately connected with 

 tlie Foraminifera on the one hand, and in their polymorphic 

 Plasmodia &c. so much resemble the Mycetozoa on the other, 

 it will be seen that in 1858-57 1 described and illustrated 

 the tests of Amoeba verrucosa and Eugbjpha alveolata in au 

 etfete state, respectively charged with a number of spherical 

 colourless cells similar in form and composition to the spores 

 of the Mycetozoa (' Annals,' vols, xviii. and xx. pis. v. and i. 

 tigs. 26 &c. and 13), and following their stages of develop- 

 ment after the same manner as that adopted for the spore of 

 the Mycetozoa, it has been found that : — 



(1) The spore or reproductive body of these E-hizopoda is 

 spherical, about l-136Gth inch in diameter in Amoeba verru- 

 cosa (' Annals,' 1857, vol. xx. p. 40, pi. i. fig. 13, a, b) and 

 about l-4000th inch in Eaglypha alveolata {ib. vol. xviii. 

 p. 244, pi. V. figs. 27 and 28), also that it consists of a trans- 

 parent colourless cell-wall or cortex filled with equally colour- 

 less granuliferous plasma, (2) On germination (which has 

 not been actually seen) the cell- wall or cortex may be fairly 

 inferred to burst, as in the Mycetozoa, and the granuliferous 

 plasma to come forth in the form of a colourless monociliated 

 ])olymorphic body, possessing a nucleus and a contracting 

 vesicle. (3) The cilium becomes retracted and the polymorphic 

 body assumes the condition of an Amoeba. (The presence of 

 the cilium and its retraction in the young Rhizopod has been 

 seen in the instance of a mother-cell in which the progeny 

 came forth one by one in the form of monociliated polymor- 

 phic bodies, retracted their cilium respectively, and, putting 

 lorth pseudopodial rays, assumed the form of an Actinophryn 



* With the marine species I have nothing to do hers 

 Ann. db Mag. N. Hist. Ser. 6. Vol. iv. 7 



