74 H. MAESHALL WARD. 



Observed in such a suspended drop of water as that described above, 

 the first changes noticed in the germinating spore are as follows. The 

 spore slowly swells, the nucleus being very distinct, and a slight pro- 

 tuberance makes its appearance at one side : over this protuberance it 

 is easy to see that the cell wall is distinctly thinner, and hence this 

 portion of the spore looks paler, from the two facts that the same 

 amount of pigment is distributed over a larger area of thinner mem- 

 brane, and the translucent refractive protoplasm shines through with 

 a sort of pearl-like lustre. 



Meanwhile the protoplasm in the interior begins to move very 

 slowly, and in some cases it is certain that a vacuole is already formed 

 which begins to pulsate feebly at long intervals. As the protuberance 

 becomes more pronounced, the movements become a little more active, 

 and the vacuole pulsates at intervals of from one to two minutes : 

 minute brilliant granules can now be distinctly observed to change their 

 positions in the hyaline protoplasm. Very soon after this the lateral 

 protuberance ruptures, the crack slowly extending (figs. 11 and 14) 

 and the contents becoming exposed : all these phenomena may occur 

 in from 4 — 12 hours after sowing the spores. 



In favorably situated spores the contents may now be seen to divide 

 into two, and two nuclei (in one case two vacuoles also were seen) 

 make their appearance. In some examples the following phenomenon 

 was observed : the protoplasm thus exposed to direct contact with the 

 water suddenly retreated into the spore again, then slowly commenced 

 to emerge as before and shrank back suddenly again. This was re- 

 peated several times before the protoplasm escaped as two myxamoebse. 



In other cases, it may be observed that, in a few minutes after the 

 appearance of the two nuclei, there are two amoeboid masses of proto- 

 plasm in the spore, one of which slowly emerges, followed soon after- 

 wards by the second one. Thus, in fig. 15 the spore had developed 

 the protuberance at 11.40: this ruptured at 1 2. 10, and the naked 

 protoplasm rapidly withdrew as if it had sustained some shock on con- 

 tact with the environment : at 12.22 one of the myxamoebse was seen 

 slowly emerging (the other one of the two having escaped about one 

 minute previously was now slowly creeping about on the surface of 

 the spore) and at 12.24, when nearly completely emerged, it suddenly 

 withdrew into the spore, as if some shock had irritated it. At 12.26 

 it protruded again, and in the course of the next minute escaped as a 

 free myxamoeba. During the course of the next few minutes both 



