NUCLEI IX THE MTCETOZOA. 537 



halves, and also to extend to the now widely-diverging poles 



(figs, 6 and 9), while the nuclear wall has vanished ; after this 



the spindle-fibres disappear, and each daughter nucleus becomes 



enclosed in a spore. The chromatin elements composing the 



nuclear plate, when seen under the highest powers, appear as 



elongated curved bodies, though their exact shape cannot be 



made out, nor can any indication of longitudinal splitting be 

 detected. 



From the appearances above described, there seems to be 

 strong evidence that the process followed in these minute nuclei 

 is of the same character as that observed in those of larger 



size. 



1 wish to call attention to a remarkable change that took place 

 in the behaviour of the plasma of Badhamia at the time of the 

 appearance of the spindle stage. Until the condition which I 

 take to be the coil was reached, the plasma, when spread on the 

 cover-glasses, was viscid and smeared with some difficulty, forming 

 lumpy aggregations, but as soon as the spindle had formed it 

 spread like cream in an even layer. The stainings showed, as 

 had before been observed to some extent in Comatricha and 

 Physarum, that at the time when the viscid condition ceased, the 

 plasma broke up in irregular masses enclosing numerous nuclei 

 with the nuclear plate in various stages of division ; as the 

 daughter nuclei separated, a further breaking up took place, until 

 each dividing nucleus was surrounded bv a definite amount of 

 plasma of the capacity of two spores; this again constricted to 

 form the spores. The process in these species is very rapid. In 

 Trichia fallax, on the other hand, the plasma does not break up 

 until the final spore-formation takes place and the daughter 

 nuclei have separated*. 



The small nuclear bodies before referred to seen in the prepa- 

 rations of Physarum leucophaum and Trichia fallax may, perhaps, 

 be abortive nuclei. In Comatricha Friesiana they could not be 

 found either before or after the formation of the spores, though 

 more than 30 stainings of the critical stages were examined. In 

 Trichia fallax they were not present in the earlier conditions, 



* Xote.— Since writing the above, we have made a successful series of stainings 

 of the sporangia of Didymium squamulosum, Craterium vutyare,n\\d Badhamia 

 panicea. In all of these the breaking up of the spore-plasma took place in the 

 same manner as in Badhamia utricularis, the dividing nucleus always being 

 surrounded by a mass of two spores' capacity before the final division into spores. 



