53i 
in Pinus and Thuja. 
the lumps are quite variable in respect to both size and number. In 
L ilium he states that the number is often greater than that of the somatic 
chromosomes, and does not reach this number by subsequent fusions. In 
other genera he has, however, reported conditions which are more in 
harmony with the idea of prochromosomes. Overton (’05) states that in 
Thalictrum purpurascens> Hellehorus foetidtis , and Campanula grandis , the 
chromosomes of the last somatic division remain visible in the nucleus 
of the spore-mother-cell as rather large lumps, which resemble the somatic 
chromosomes, and which always coincide with them in number. He speaks 
of these accordingly as ‘ prochromosomes ’. These lumps he finds to be 
generally arranged in pairs. The linin strands connecting them are always 
arranged parallel, and some of the chromatin not contained in the bodies is 
distributed along the strands. Previous to the synaptic phase, it often 
happens that the prochromosomes become broken up and distributed along 
the threads of linin, and thus there are formed two fine continuous threads 
of linin studded throughout with chromatin. In this condition synapsis is 
reached. 
In neither Pinus nor Thuja , as stated above, does the number of 
chromatic bodies ever approach the number of somatic chromosomes. 
These bodies are always quite numerous, but they do not appear to become 
so finely granular and dissected as seems to be the case in Lilium. There 
is also no tendency toward an approximation in pairs. The linin threads 
are not arranged parallel to each other, but rather anastomose in all 
directions. The chromatin is often distributed for some little distance 
along these strands, but it is confined principally to the chromosomes them- 
selves. It often happens that two or more bodies are found lying together 
in close proximity, but no good reason is seen for interpreting this as 
an indication that they are preparing for fusion in pairs. Equally clear 
is it that an occasional linin thread follows for a short distance the same 
course as one lying near it (Fig. i), but, judging from the extreme rarity 
with which this phenomenon occurs in these genera, it is my opinion that 
this is merely a matter of chance and has no significance whatever. 
Allen, Guignard, Berghs, Cardiff, and others have reported conditions 
for many genera of plants in which the linin threads become arranged 
parallel to each other, and then by the reticulation and distribution of the 
chromatin along these threads two fine spirems are formed prior to synapsis. 
During the synaptic phase these spirems fuse more or less completely into 
one. In both Pinus and Thuja the first indication that the synaptic con- 
dition is approaching is the withdrawal of the nuclear network toward one 
side of the cavity. There is no evident change at this time in the content 
either in structure or staining reaction. The chromomeres retain approxi- 
mately the same size as before, and the linin still retains its characteristic 
staining reaction. The net becomes somewhat contracted towards the side 
O o 7 , 
