MATIIUATION OP OVUM IM KOHINUS ESCgLENTUS. 213 



have said above, it differs from that type in certain important 

 particulars, and agrees closely with the Cyclops type. 



Each half of the compound chromosome or tetrad is a short 

 rod, showing at its ends small spherical bodies. If these 

 spheres are to be interpreted as separate elements of the tetrad, 

 there being absolutely no trace of a second longitudinal 



division, I cannot represent the figure as in Ascaris -^i^ . If 



one adopted Haecker's idea of a suppression of the last trans- 

 verse segmentation of the spireme thread, the figure could 



a [ a 

 with perfect propriety be represented | | , assuming each 



b'b 

 sphere to be the equivalent of a single chromosome. Follow- 

 ing up this formula through the first and second divisions, 

 it would Avork out as follows : 

 Prophase. Metaphase. Anaphase. Telophase 



I. 2. 2.7 3. 4. 5. 



Text-fig. 2. — Scheme of first maturiition division. 



1. Double-rod piopliase figure or tetrad; first longitudinal split. 



2. Double-rod figure placed radially on spindle; opening out of daugliler 

 eliromosomes in plane of first cleavage. Profile view. 



2tf. Same in face view showing beginning of second longitudinal split. 



3. Elongation of chromosomes. 



4. Separation of daughter elnoniosonics. Each is much contracted, arid 

 the second longitudinal split has further extended, so as to give rise to a V. 



5. Com|)letion of second longitudinal split, converting Mie V's into double- 

 rod figures, which are tlie granddaughter chromosomes. 



