306 THOS. H. MONTGOMERY, 



parts are continuous, without interruption, and by virtue of their con- 

 tinuity with the other corresponding linin bands of the other chromo- 

 somes, form within the nucleus a single continuous linin thread , or 

 spirem. One portion of this linin spirem has, however, disappeared 

 apparently from the nucleus, namely that which formed the connective 

 fibres in the metakinesis preceding; but the disappearance of these 

 threads has not effected any discontinuity of the linin spirem, since 

 the connective fibres were formed as branches of this spirem. 



Of this spirem in the synapsis the axial and the central linin 

 threads can be seen with great clearness whenever they are suitably 

 stainedand happen to lie exactly in the plane of the section (Figs. 64 — 

 84, 88). The distal linin threads, on the other hand, are very delicate 

 and much more difficult to see; this is due partly to the fact that 

 the distal ends of the chromosomes are generally quite closely ap- 

 posed to the nuclear membrane, and partly due to the fact that the 

 distal threads are usually much twisted and bent in their course. 

 The main reason, therefore, for my concluding that they connect the 

 distal ends of separate chromosomes, lies in the fact that later, in 

 the prophase of the 1st maturation division, this connection can be 

 made out very clearly; and it is probable that this connection has 

 not arisen in the prophase for the first time, but that it is a per- 

 sistence of the condition in the preceding stages. 



About the beginning of the synapsis other, more delicate, linin 

 structures appear. These are fine fibrils which join the chromatin 

 granules of one chromosome with those of another (Figs. 73, 77, 80, 

 83, 88 B, D, E, G, M, 89, 91—97); in this way the granules of 

 separate bivalent chromosomes are connected, as well as the granules 

 of the two univalent chromosomes which form a bivalent one. Certain 

 of these delicate fibrils also seem to join chromatin granules with 

 the surface of the nuclear membrane. Each of the fibrils is certainly 

 attached at one end, and probably at both. To each chromatin 

 granule there would appear to be attached at least one of these fibrils. 

 What the origin of these fibrils is can only be conjectured, for I have 

 found no method of determining their process of formation. They 

 can have no relation to the connective fibres, for the latter were 

 attached to the distal ends of the chromosomes. The mantle fibres 

 can no longer be determined as such, and they were described as 

 having disappeared; these fibres were attached to the central ends of 

 the chromosomes, and it is quite possible that some of them persist 

 as fine fibrils connecting the central ends of the chromosomes with 



