1909] CURRENT LITERATURE 477 
tuitous alteration in length by turgor changes; but he thinks this explanation 
precluded by the different behavior of the plants with sugar solutions under aerobic 
and anaerobic conditions respectively. Because of the great increase in growth 
late in the culture period, he also rejects the possibility of anaerobic growth being 
due to residual oxygen, even though there must be some not removable by his 
methods. Taking everything into consideration, NABOKICH believes that aer- 
obic and anaerobic growth have no necessary connection, being called forth by 
different factors 
A reading eS this paper leaves one unconvinced that the author has estab- 
lished his point, in spite of the apparently prodigious labor the prolonged and 
very difficult research has involved, with results of minimal consequence. It 
seems another case of the mountains in Jabor.—C. R. 
Hybridization.—GicL10-Tos? publishes an attempt to reach theoretical] 
explanation of the varied phenomena of hybridization. His views are based on 
his theory of ‘‘biomolecular addition” which may be briefly stated. He supposes 
that a fertilized egg, A, consists of a series of molecules a, 6, c,d, ¢, . . . n 
that after a series of chemical transformations owing to assimilation hers arrive 
finally at a chemical constitution m,n, 0, p, q, . after which each divides 
into 2a, 2b, 2c, 2d, 2e,...., sak ice to ile ceusnad condition. When 
this occurs, “‘regeneration of the germ” would be complete. In sexual repro- 
duction if 4 nd Bg represent the biomolecules of he two germ cells, the 
Organism developed from the fertilized egg, AB, might have the capacity of 
regenerating the whole “biomolecule” which formed it, in which case we would 
have parthenogenesis; or if complete regeneration is not possible we will have 
sexual reproduction, each of the germ cells regenerating a part. The case in 
plants, in which both sexes are usually present in the same individual, is not spe- 
cifically considered. 
rom this point of view the writer interprets sexuality, synapsis and reduction, 
fertilization and hybridization. It is further supposed that the zygote AB, while 
retaining an equal number of male and female biomolecules, yet in the ontogeny 
undergoes certain modifications, so that the resulting germ cells will be ¢M and 
N?2; and that the constitution of these is such that they can be added to each 
other (“biomolecular addition”) to produce again ¢AB9. 
On this basis the results of crossing are considered from an a-priori point 
of view and a number of “laws” are enunciated. Explanations of Mendelian 
Segregation, blending, and other phenomena of hybridization are offered, and 
predictions made as to the results of cross-breeding reciprocal hybrids. The 
formal character of the hypothesis makes it probable that it will fail to conform 
to many of the facts of hybridism, but its viewpoint is very suggestive. For the 
details of its application see the original paper.—R. R. GATEs. 
32? GiGLIo-T 08 ERMANNO, L’eredit& e le leggi razionali dell’ ibridismo. Biologica 
2:no. Io. pp. 3 
