McAllister—Cytology and Embryology. 643 
mediately upon recovery from synapsis and is followed by a 
period of a more or less distributed condition of the chromatin. 
Janssens’ stage of nuclear tension which may be comparable 
with the second contraction stage follows a definite bouquet 
stage. I have cited other cases [Eisen (20), Van Mlolle (57) 
and Schleip (88)] of a definite contraction stage occurring in 
the reduction divisions of animals which has been preceded by 
a bouquet stage and a period comparable to the stage of uni¬ 
formly distributed spirem. It seems clear therefore that no 
relation can exist between the bouquet stage and the second 
contraction figure. 
The work of Riickert (87) and Hacker (36) on Cyclops has 
shown that the parental chromosomes remain separate for a 
time at least in the nuclei of the diploid individual. The work 
of Moenkhaus (36) on hybrid fishes further suggests that there 
is not a fusion of the parental chromosomes at the time of fer¬ 
tilization but a gradual mingling of the distinct chromosomes 
in the nuclear cavity. 
In Pinus Blackman (8), Chamberlain (15) and Miss Fergu¬ 
son (26) as mentioned above, report that the parental chromo¬ 
somes retain their identity during the first mitosis of the fer¬ 
tilized egg. The work of Woycicki (109) on Larix, of Murrill 
(70) on Tsuga, of ISTichols (71) on Juniperus, as well as that of 
Shaw on Onoclea (91*) and Dublin (19) on Pedicellina demon¬ 
strate similar phenomena. 
The parental nuclei in the diploid generation of the rusts as 
shown by Blackman (9), Christman (6) and by others, re¬ 
main perfectly distinct throughout the entire diploid genera¬ 
tion. The fact that in a large number of cases among animals 
the sex nuclei at the time of fusion have their chromosomes al¬ 
ready organized so that at least during the first cleavage of the 
fertilized egg the parental chromosomes must remain distinct 
bears out the general conclusion that the paternal and maternal 
chromsomes remain distinct during the first division, at least, of 
the diploid generation. 
The pairing of the chromosomes as described for Funkia, 
Galtonia, Yucca, etc. shows that there is a tendency toward a 
