1909] GATES—CHROMOSOMES IN OENOTHERA IQI 
synapsis. This thread then becomes rearranged into regular loops 
converging to one side of the nucleus and forming the “bouquet” 
stage of E1sEN (6). This stage is characteristic of many animals, 
in which it has been described by JANSSENS and DuMEz (17), STEVENS 
(34, 35), MARECHAL (25), and JorDAN (18), to mention only a few. 
Each loop is composed of two chromosomes arranged end to end. 
Similarly the spirem in Fucus is made up of the maternal and paternal 
chromosomes arranged endwise in a single thread. This is what I 
have shown to be the case in Oenothera (11), although Oenothera 
has no typical “bouquet” stage, nor has any other angiosperm, so 
far as I am aware, though the second contraction phase, character- 
istic of various forms, probably corresponds to it. OVERTON (30) 
states that this stage does not occur in the plants with short chromo- 
somes which he has examined, yet it occurs in Oenothera, in which 
the definitive chromosomes are very short and frequently almost 
globular. The second contraction phase is a well-marked stage of 
meiosis in Oenothera. 
I may mention a few of the recent accounts involving an end-to- 
end arrangement of the chromosomes to form the spirem (telo- 
synapsis). Morrtrer finds (29) that in Podophyllum, Lilium, and 
Tradescantia the two members of each bivalent chromosome were 
not side-by-side in the spirem, representing the halves of the longi- 
tudinally split thread, but were arranged end-to-end in the chromatic 
thread. Lewis (22), in a study of Pinus and Thuja, finds no pairing 
of threads, but cross-segmentation of a single post-synaptic spirem to 
form the chromosomes. Just what relation his fig. 15, which indi- 
Cates a reticulum as occurring about the time of chromosome forma- 
tion, bears to the other stages, it is hard to say. Lewis ventures the 
Opinion that the second division is probably qualitative, but with a 
manifest lack of evidence to support it. SCHAFFNER (33), in Agave, 
nds bodies which he believes are bivalent prochromosomes, and a 
Single spirem which segments to form the twelve bivalent chromo- 
somes. 
Among very recent accounts of reduction which involve a longi- 
tudinal pairing of threads (parasynapsis) may be mentioned that 
of Grécore (16), with figures involving the critical stages in Lilium, 
smunda, and Allium; YAmMaNoucut (38) in Nephrodium; OVER- 
