242 Morphologie, Teratologie, Befruchtung, Cytologie. 



embryonic tissue. (Proc. Camb. Phil. Soc. XVII. 5. p. 369— 

 379. 2 pl. 1914.) 



In the present paper an account is given of certain features in 

 the general developinent and the cytology of the adventitious roots 

 of Stratiotes aloides L., which may be summarised as foUows: 



A. Anatom ical Results. 



1) The apex of the young adventitious root is clothed in a uni- 

 form cap of tissue, in which no distinction can be recognised be- 

 tween a pericyclic root cap and an endodermal digestive-sac. In 

 this respect the results agree with those of D. G. Scott and are 

 opposed to those of Van Tieghem and Douliot. 



2) The origin of the lacunae of the middle cortex is shown to 

 be due to differences in the rate of growth of the different tissue- 

 regions of the root. 



B. Cytological Results. 



(The cytological results here recorded are of the nature of a 

 preliminary Statement. It is hoped to deal with the subjects raised 

 in greater detail in a later paper). 



1) The nuclei of the young vessels and of the 3^oung root hairs 

 are shown to be relatively of great size, — a feature which possibly 

 indicates unusual plasticity in the nuclei of this plant. 



2) In the stem and leaf, bilobed nuclei and cells with more 

 than one nucleus are shown to occur, but this pecularity is much 

 more important and conspicuous in the young adventitious roots 

 where it occurs in the root-cap, cortex and stele. These observa- 

 tions have been made upon plants collected in 1910, 1911 and 1912, 

 from two different localities, which where fixed and stained in 

 various ways. It is suggested that amitosis Supplements karyo- 

 kinesis in the early development of the adventilions roots. 

 The benaviour of the nuclei is considered in relation to the life- 

 histor}'^ of the species, and the paper concludes with a brief discus- 

 sion of the significance of amitosis, in which it is pointed out that 

 the present case seems to be unique among recorded examples, in 

 respect of the immature condition of the tissues in which it occurs. 

 It lends Support to the view that amitosis is by no means ahva5'-s 

 a senile phenomenon. Agnes Arber (Cambridge). 



Cavers, F., Chondriosomes (Mitochondria) and their 

 significance. (New Phyt. XIII. p. 96-106. 1914.) 



The present paper (of which a continuation will appear later) 

 forms a critical review of the State of our knowledge of chondrio- 

 somes. It opens with an account of the zoological literature dealing 

 with those bodies in the animal cell which have been variously 

 termed chondriosomes, granula, bioblasts, mitochondria, chondrio- 

 miten, chondriomes, chromidia, chromidial apparatus, sphaeroblasts, 

 histomeres, trophochromidia, somatochromidia, granulochromidia, 

 plastosomes, plastokonts, plastochondria, etc. The conclusion is 

 reached that these are all cssentially homologous structures, and 

 that they act as the carriers of the hereditary qualities of the cyto- 

 plasm, just as chromosomes carry those of the nucleus. Chondrio- 

 somes in plants are then discussed, in connexion with the work of 

 Meves, Beer, Tischler, von Derschau, Lundegard, Le- 

 witsk^^ Pensa, Guiliiermond and other C3^tologists. The most 

 important recent discovery in this field appears to be that of the 



