190 MAULSBY W. BLACKMAN. 



act nature of the changes taking place cannot be learned. Sev- 

 eral facts are however very apparent. Of these one of the most 

 important is this : At the time when all the other morphological 

 constituents of the mass of chromatin are undergoing very funda- 

 mental changes, one of these elements remains unaltered. While 

 all of the neighboring chromosomes lose their definite outlines 

 and are changed into elongated threads of a granular structure 

 one, the accessory chromosome, does not participate in this 

 metamorphosis but apparently retains all of the properties char- 

 acteristic of it during metakinesis. While this difference in con- 

 sistency is the most apparent discrepancy existing between the 

 accessory chromosome and the ordinary chromatic elements, as 

 we shall see presently, it is by no means the most important one. 

 As the telophase advances the chromosomes continue to 

 lengthen out into long threads. At first, as we have seen, these 

 filaments form a dense mass which is surrounded by no mem- 

 brane marking off the nuclear area from the cytosome. As 

 the chromosomes become more diffuse this mass also becomes 

 less dense and the individual segments are not so closely ap- 

 posed to each other. This stage is shown in Fig. 4, where the 

 chromatin of each of the two daughter cells is in the form of an 

 irregular, more or less closely knotted, mass of granular fila- 

 ments. This mass is contained in a large clear vacuole hav- 

 ing no visible network of linin or cytoplasm and bounded by no 

 definite membrane. The appearance of the chromatin grouped 

 in a diffuse mass upon one side of this vesicle suggests very 

 strongly a comparison between this stage in Scolopcndra and the 

 " synapsis " in elasmobranchs, as described by Moore, '95, 

 and later in different objects by numerous other authors. In all 

 the reported cases with which I am acquainted, however, this 

 massing of the chromatin upon one side of the nuclear vesicle 

 occurs at a considerably later stage than the early or mid-telo- 

 phase. Paulmier '98, and Montgomery '98, both figure it as taking 

 place after the formation of the chromatic spireme. McClimg, 'oo, 

 denies the normal existence of any such massing of the chromatin 

 in the Acridities, referring such appearances to the distorting 

 effects of the fixing reagents employed. By the majority of in- 

 vestigators upon male cells this massing of the chromatin is used 



