488 - SECTIONAL TRANSACTIONS.—K. 
13. Mr. J. C. WatuEr.—Photo-electric Changes in Green and While 
Leaves. 
Variegated geranium leaves show electrical changes in response to light 
similar to those of green geranium leaves partly shielded by dark paper, the 
chlorotic portions of the former corresponding to the shielded portions of the 
latter. Green petals of Hydrangea act similarly to green geranium leaves, while 
white petals give little response. This is further evidence that the photo- 
electric change is specially associated with the chlorophyll function. 
The ratio between intensity of light and electrical response is as might be 
expected from other physiological ratios. ; 
A leaf tested after being kept under normal conditions of sunlight is 
different from the same leaf after many hours in the dark. 
Such comparison of photographic records of electrical response under different 
biological conditions is more likely to be instructive than the analysis of indi- 
vidual curves. 
14. Dr. M. Witson and Miss E. J. Capman.—The Life-history and 
Cytology of Reticularia lycoperdon. 
Shortly after spore germination the blepharoplast arises from the nucleus 
and passes to the periphery of the cell, the flagellum then developing from it. 
Throughout its existence the blepharoplast is connected to the nucleus by a 
cone-shaped structure, the ‘ Verbindungstiick.’ The swarm-cell is of the usual 
type. Before division the flagellum is retracted, the blepharoplast divides, 
and the two portions function as centrosomes, a paradesmose being formed 
between them. ‘The paradesmose gives rise to ‘the spindle; four chromosomes 
are present. The flagella of the daughter cells grow out from the centrosomes 
before cell division is completed. 
Fusion normally takes place between two motile swarm-cells. The flagella 
are withdrawn after fusion, and the cells become rounded and gradually coalesce. 
Nuclear fusion follows, producing a uninucleate plasmodium. This at once 
becomes amceboid and engulfs and digests swarm-cells which have not undergone 
fusion. The nucleus of the plasmodium soon divides, eight chromosomes being 
present, and division continues, producing a multinucleate plasmodium. 
Under natural conditions the plasmodium emerges from the wood at a 
number of places situated close together, the separate portions later on coalescing 
to form the large ethalium. Two nuclear divisions have been seen in the 
plasmodium just before spore formation. These are the meiotic divisions. 
The divisions are intranuclear and centrosomes are not present. In the first 
meiotic (heterotype) division four U-shaped chromosomes are present. This is 
rapidly followed by the second (homotype) division, in which the nuclei occur 
in pairs. The meiotic divisions appear to take place only in certain areas of 
the plasmodium, and it is in these areas that spore formation goes on. The 
remaining cytoplasm and associated nuclei degenerate, and the resulting material 
forms the incomplete internal partitions and external walls of the ethalium. 
The sporogenous portions become divided up by irregular lines of cleavage until 
uninucleate masses are produced which form the spores. 
15; Prof. H. H. Dixon, F.R.S., and Mr. N. G. Bauu.—The Vascular 
Supply of the Haustorial Cotyledon of Lodoicea and Pheniz. 
Close beneath the absorbent surface of the haustorium there is a net- 
work of bundles. This network is connected with the embryo by bundles which 
traverse the petiole longitudinally. The connecting bundles contain about as 
much phloem as xylem. The cross-section of the phloem in the haustorium is fe 
much greater than that of the xylem. In the haustorium of Lodoicea large 
tubular cells pass out from the sheath of the bundles into the surrounding 
parenchyma; sometimes chains of these cells connect the sheaths of adjacent 
bundles. Sheaves of narrow tubular cells are found in the vascular parenchyma, 
which turn out into the adjoining parenchyma. ‘They often penetrate as far 
as the outer intercellular spaces of the haustorium, and there come into contact 
with the semi-fluid debris of the endosperm. 
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