j>30 PETOH : 



to vary ; normally, tho remaining protoplasm becomes liighly 

 vacuolated and juay therefore push out the last spore. I have 

 liowever seen a spore separate from tlie protoplasm (which was 

 still dense and granular) and advance towards the open end, 

 leaving a gap of about 10 \x ; the protoplasm then advanced 

 and diminished the gap to about 5 [i, after which the spore 

 moved forward again ; in this case the residual protoplasm 

 did not possess a terminal wall. It seems probable that the 

 extrusion of the last-formed spores may be in part a capillarity 

 effect. It is not, liowever, uncommon to find one or more 

 spores left permanently in the tube. 



The time of extrusion of the earlier conidia occupies from 

 three to six minutes. In one instance, the fifth was extruded 

 in four minutes, and the sixtli in six minutes. In another 

 case, the nineteenth was extruded in five minutes thirty-five 

 seconds, the twentieth in five minutes five seconds, and the 

 twenty-first in six minutes twenty seconds. 



When the conidia are extruded, they adhere by their ends 

 in a ch,ain. If the conidiophore projects from the surface of a 

 liquid or solid medium, the chain soon falls over and the 

 conidia come to lie in a mass beneath the apex of the conidio- 

 phore. When the conidiophore lies in a film of water on a 

 cover glass, the first three or four conidia are pushed out in a 

 straight fine along the glass ; the force required to push them 

 further is evidently greater than the cohesion of the spores 

 can withstand, for the chain is then bent and the succeeding 

 conidia are pushed up by the side of the former, so that they 

 come to be arranged at first in more or less parallel lines and 

 later in an irregular group ; in these cases, when a conidium 

 has to overcome the pressure of the mass of spores in front of 

 it, the final stage of its extrusion occurs with a distinct jerk. 

 When the conidiophore hes within a hanging drop, the spores 

 remain in contact and form a long chain containing up to 

 eighty or more. Frequently the chain assumes a zigzag pattern 

 as it is pushed forward. The shapes assumed are exactly those 

 obtained by placing dominoes end to end in one line and 

 pushing them across a table. 



The extrusion of the microconidia, as seen in Ceylon, is a 

 steady continuous process. It is probable tliat tlie times 



