616 Morphologie, Teratologie, Befruchtung etc. — Varietäten etc. 
eens, Ccilyccinthiis floridus, and Richavdia afvicanci. The description 
of his results is followed by a survey of the literature and a general 
discussion on the permanence of the chromosomes and the nature 
and significance of the reduction division. He arrives at the following 
conclusions: 
In the resting somatic nuclei of Thalictrum purpurascens and 
Calycanthus floridus two heterogeneous spirems can be distinguished, 
and it is probable that these spirems remain distinct throughout the 
life-history of the sporophyte. In the resting nuclei of the germ cells 
of these plants and of Richavdia africana prochromosomes are pre¬ 
sent in the same arrangement and form as in the somatic nuclei. 
[Prochromosomes, or bodies corresponding thereto, which bear some 
definite relation to the chromosomes either in number, form or size, 
have now been reported by five authors in the cases of nineteen 
plants.] Düring the synaptic contraction the parental spirems remain 
distinct. The actual interchange of parental parts or influence pro- 
bably occurs during the post-synaptic spirem stages. There is no 
continuous chromatic spirem at any stage. There is in these plants 
no second contraction figure, and this second contraction, in the 
cases in which it has been described, is regarded by the author as 
having no significance in the reduction process. Each of the two 
parts composing each diakinetic chromosome represents a somatic 
chromosome. No folding process to form these bivalent chromosomes 
seems possible. The heterotype divisions separate entire somatic 
chromosomes. A. Robertson. 
Pond, R. H., Emergence of lateral roots. (Bot. Gaz. XLVL 
410—421. Dec. 1908.) 
Contrary to the Statement ofVan Tieghem it is found that in 
Vicia Jaba and Lupinus albus there is no sign of Chemical corro- 
sion of the cells of the cortex by an emerging lateral root. Micro- 
scopic examination shows a compression and collapse of cortical 
cells, but no signs of solution of the walls or contained starch grains. 
The turgor of the cortical cells was measured and found to be less 
than that of the advancing lateral root tip. Experiments carried on 
with roots encased in plaster showed that one root cannot penetrate 
the intact cuticle of another, but readily passes through the cortex 
if the cuticle has been punctured at the point of application of the 
second root; here also no signs of corrosion were observed. It is 
concluded that in the plants mentioned the lateral roots exert a 
mechanical and not a digestive action upon the surrounding tissue. 
M. A. Chrysler. 
Darbishire, A. D., On the result of Crossing Round with 
Wrinkled Peas, with Especial Reference to their Starch 
Grains. (Proc. Roy. Soc. Lond. B. LXXX. p. 132—125. 1908.) 
The paper deals with further investigations upon the nature of 
the starch grains in round and wrinkled peas ( Pisum sativum ), and 
in the hybrid between them. In the round pea, such as Eclipse, the 
starch grains are single and potato-shaped; a few small grains also 
occur. In the wrinkled pea, such as British Queen, the grains are 
compound, each consisting of a number of pieces held together by 
a substance which is probably of a different nature from the pieces 
themselves. There are also, in the wrinkled peas, a number of very 
small single round grains. In addition, the author has found in 
