CURRENT LITERATURE 
NOTES FOR STUDENTS 
Forest geography of New Je1sey.—HAarPER subdivides New Jersey into 
nine forest regions, most of which form approximately parallel belts traversing 
the state from northeast to southwest.‘ Each of these is discussed in turn and 
the characteristic species noted. The most abundant tree in the state is 
Pinus rigida, but the most widely distributed tree probably is Quercus alba, 
which occurs in all of the nine forest regions; Acer rubrum is not far behind 
Quercus alba in this respect. Evergreen species probably make up about 40 
per cent of the forests of the state—H. C. CowLEes 
Random assortment in inheritance of distinguishable homologous chromo- 
somes.— Miss CAROTHERS,? from her work on — has already reported 
the occurrence of homologous chromosomes which could be identified one 
from the other by a size difference. Furthermore, since the form of a given 
homologue is constant for the individual, she has been able to demonstrate, 
from a study of a number of individuals of the population, that these hetero- 
morphic homologous chromosomes (3 pairs) have a random segregation in rela- 
tion to each other and to the sex chromosome. In the present paper, she 
actually follows these chromosomes from parent to offspring, making a cyto- 
logical examination of the parents after they have been allowed to reproduce, 
and later an examination of the resulting progeny. Size, shape, and point of 
attachment of spindle fibers all seem to be practically constant heritable char- 
acters, by which the author identifies the individual chromosomes, and shows 
that their recombination in the progeny is according to the laws of chance. 
In the author’s material one can say in regard to the chromosomes which 
enter the gametes, just as certainly as of a pair of contrasting unit characters 
which segregate in the F, generation, that this one was contributed by the 
father and that one by the mother. This amounts to a direct demonstration 
of those assumptions as to the behavior of the chromosomes in inheritance 
which have been necessary to account for the workings of Mendel’s law. It is 
hoped that eventually such structural variations of the chromosomes will be 
correlated with the resulting somatic characters of the individual—M. C. 
COULTER 
* Harper, R. M., A sketch of the forest geography of New Jersey. Bull. Geog. 
Soc. Philadelphia 16:107-125. pls. 3. 1918. 
2 CaroTHERS, E. ELEANOR, Genetical behavior of heteromorphic homologous 
chromosomes of Circotettix (Orthepters). Jour. Morph. 35:457-473- 1921. 
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