402 LOTSY, CURRENT THEORIES OF EVOLUTION. 
The result therefore simulates mendelian segregation, while the 
real cause of the diversity is unequal chromosomedistribution.. 
The most peculiar kind of hybrids discovered so far however, is 
that of some sugarcane hybrids as described by BREMER. A cross 
of a gamete of Saccharum officinarum with 40 chromosomes with 
one of Saccharum spontaneum with 56 chromosomes gives a hybrid 
with 136 chromosomes instead of one with 96 chromosomes as. 
one would have every right to expect. This curious result is caused 
by a longitudinal splitting of each of the 40 officinarum chromo- 
somes previous to pairing, so that 80 offictnarum chromosomes 
meet 56 spontaneum chromosomes, which gives a total of 136. The 
actual pairing which subsequently occurs leaves no singles so that 
probably 56 officinarum chromosomes pair with 56 spontaneum 
chromosomes, while the rest of the officinarum chromosomes, 
twenty-four in all, pair with one another. We consequently get 56 
hybrid disomes and 12 pseudo-hybrid disomes in the zygote. 
This fact, that chromosomes can split longitudinally, previous to 
pairing with others, has considerable theoretical importance in 
connection with WiNGE's hypothesis of the derivation of the in- 
dividual chromosomes of a particular set from different sources, by 
a hypothetical process which he calls indirect chromosome-binding. 
This process is imagined to take place in the way indicated on 
p. 403."Fig. 2. 


