756 
Digby .— The Somatic , Premeiotic, and 
Fig. 21. Still later telophase, in which the remains of some of the ‘ chromosome bands ’ are to 
be seen, whilst the others have broken up and have lost their identity. There is a clear space round 
the nucleolus. 
Fig. 22. Very early prophase, showing the parallel arrangement of the linin as strands of beads, 
some strands having already concentrated into chromosome segments. 
Figs. 23 and 24. Progressive stages in the concentration of the linin to form the chromosome 
segments. 
Fig. 25. Still further concentration; the linin is now in the form of thickened masses, showing 
parallelisms in their sides. 
Fig. 26. Late prophase, showing segmented spireme. 
Fig. 27. Slightly later stage in which the spireme segments have thickened considerably. The 
segments are homogeneous. 
Fig. 28. Root. ‘ Crystalline’ structures in the nucleus, ?z., nucleus ; c. b., crystalline bodies; 
r., refractive dots. 
Fig. 29. Division of nucleoli by constriction. 
Fig. 30. Telophase of last archesporial division. There is the same alveolization of the chro¬ 
mosomes resulting in the formation of paired threads as in the telophases of somatic divisions. 
Fig. 31. Polar view of a nucleus in telophase of the last archesporial division. 
Fig. 32. Tapetal nucleus in early prophase, showing parallelisms in its nuclear contents. 
Fig. 33. Heterotype prophase. The telophase of the last archesporial division passes imper¬ 
ceptibly into the prophase of the heterotype division. The linin shows great irregularity in the 
size of its particles. Note the parallelism resulting from the alveolization of the chromosome segments. 
Fig. 34. Nucleus in which portions of the chromosomes show alveolization before the sides have 
separated. 
Fig. 35. Superficial section of a nucleus in the same stage as Fig. 34. 
Figs. 36 and 37. Show a still finer breaking up of the chromosomes, the sides of the alveolized 
chromosomes remaining in places as parallel beads or strands. 
Fig. 38 A. The linin is becoming concentrated into larger masses preparatory to going into 
synapsis. 
Fig. 38 b. Superficial section of the same stage, showing that, notwithstanding the contraction, 
the parallelism is still present. 
Fig. 39 A. The massing of the linin increases. 
Fig. 39 b. Superficial section of a nucleus at the same stage as Fig. 39 A, showing the longi¬ 
tudinal fission. 
PLATE LXI. 
Fig. 40. Further massing of the nuclear contents, but parallelisms are still to be seen. 
Fig. 41. The nuclear contents are collecting at one side of the nucleus. 
Fig. 42. Synapsis showing chromatin areas embedded in the linin substance. ‘Chromatic’ 
bodies are being extruded. 
Fig. 43. Typical close synapsis, with extrusion of ‘bodies’. 
Fig. 44. Loosening of the synaptic knot; its substance is emerging in the form of thick loops. 
Fig. 45. Some of the strands are beaded, and show longitudinal fission. 
Fig. 46. Further loosening of the knot. The strands are beaded. 
Fig. 47. Hollow spireme stage, in which the spireme is arranged in loops lying freely in the 
nuclear cavity. 
Fig. 48. The loops are beginning to concentrate towards the centre of the nucleus. Note the 
conspicuous longitudinal fission, the varied thickness of the strands, and the anastomosis between 
the strands. 
fig. 49. Nucleus which is undergoing a more prolonged ‘ hollow-spireme ’ stage. The threads 
have straightened, they are irregular in thickness, and there is anastomosis between them. 
Fig. 50. Further straightening of the spireme, which has now segmented. 
fig* 5 1 * Commencement of the second contraction. The segments are collecting towards the 
centre ; note the two lengths of spireme which are apparently joining end to end. 
Fig. 52. Beginning of second contraction. In this case the nucleus is going into second con¬ 
traction on emerging from synapsis. The sides of the loops are being drawn in parallel to one 
another, and in places they have joined side by side. 
