346 THOS. H. MONTGOMERY, 



opposite direction: the former end has been called by me the cen- 

 tral end, the latter the distal end. The linin spirem now con- 

 sists of: the axial linin threads (still hidden by the chromatin, but 

 which shortly afterwards become clearly apparent, Fig. 260); and of 

 the inter-chromosomal threads. For convenience I called each inter- 

 chromosomal fibre, from this stage on, connecting the central ends of 

 two chromosomes, a central linin fibre (Figs. 259—261, C.P.L)-, 

 and each one connecting the distal end of two chromosomes, a distal 

 linin fibre (D.P.L). Thus the linin spirem is still continuous and 

 consists of central thread, axial thread, distal thread, and so on in 

 repetition (Figs. 259, 260). There can be no doubt about the con- 

 tinuance of the axial and central threads ; the more delicate distal 

 threads are more difficult to determine, but after the stage of the 

 resting spermatocytes they appear very clearly, so that it is probable 

 that they persist through this period. It is by the agency of the 

 central linin threads that the central ends of every two univalent 

 chromosomes become approximated, so that 14 pairs of univalent 

 chromosomes result, whereby the reduction in the number of the 

 chromosomes is accomplished (Fig. 259—261). 



During the synapsis and telophase stages the chromosomes se- 

 gregate into chains of granules, and these split longitudinally whereby 

 the axial linin threads become longitudinally split, but the linin spirem 

 is still preserved as a continuous whole (Figs. 260, 261). In these 

 stages appear also dehcate linin fibrils which attach chromatin granules 

 to each other and to the nuclear membrane ; the origin of these could 

 not be determined, they may be structures sui generis or, what I 

 hold more probable, outgrowths of the linin spirem; in the diagrams 

 257 — 261 the linin spirem is colored, while in Fig. 261 these "second- 

 ary" linin fibrils are shown in black, since I could not be certain 

 that they were derivatives of the former. 



In the late telophases the outlines of the chromosomes become 

 gradually more indistinct, owing to the wide separation of their split 

 halves, but that the chromosomes retain their separateness and former 

 linin connections is very probable from certain observations given 

 above, and also from the fact that in the prophases of the 1st matur- 

 ation division the continuance of a continuous linin spirem has been 

 actually observed, both in Peripatus and Pentatoma, even though 

 there is in these prophases no continuous chromatin spirem ; as before, 

 the linin spirem is composed of axial, central and distal threads (the 

 two latter constituting the inter-chromosomal fibres). When in the 



