290 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
BOTANY. 
A. GENERAL, including the Anatomy and Physiology 
of the Phanerogamia. 
a. Anatomy. 
(1) Cell-Structure and Protoplasm. 
Kinetic Centres in Plants.* — M. L. Guignard gives further details 
of his observations on the process of karyokinesis in the formation of 
the pollen in Nymphsect , Nuphar, Limodorurn , and Magnolia. f The for- 
mation of multipolar spindles appears to be rather frequent in Nymphsea, 
but is not always followed by a definite bipolar figure. In Magnolia the 
mode of formation of the septa in the pollen-mother-cell is intermediate 
between the ordinary mode in Dicotyledons and that in Monocotyledons, 
but approaches more nearly to the latter. 
As a general rule (in both animals and plants) the attractive sphere 
encloses a distinct central corpuscle more stainable than the rest ; the 
centrosome of most authors, the “ centriole ” of Boveri. The sphere, 
properly so called, which encloses the centrosome, is of no fundamental 
importance ; it varies in size, and may disappear altogether ; its trans- 
mission from cell to cell may be observed, especially in cells in which 
the divisions follow one another in rapid succession. The morphological 
characters of the sphere also vary, according as it possesses radial striae 
or not ; it is often differentiated into two zones, an inner hyaline and an 
outer granular zone. It is the “ archoplasm ” of Boveri, the “ kino- 
plasm ” of Strasburger. 
The author then reviews the observations of other workers on the 
centrosome bodies in various families of Cryptogams. It is the for- 
mation of multipolar spindles in the first stages of division which 
constitutes the most cogent argument for the presence of centrosomes in 
Cormophytes. Centrosomes, attractive or directing spheres, present all 
possible degrees of morphological differentiation. If, as Strasburger 
thinks, the kinoplasm may take their place in their absence, it appears 
certain that the higher plants may possess differentiated kinetic elements 
having similar functions to those of the lower plants and of animals. 
Karyokinesis in Cobsea.J — Mr. A. A. Lauson has investigated the 
earliest stages in the formation of the multipolar spindle in the pollen- 
mother-cells of Cobsea scandens. The cytoplasm of the resting pollen- 
mother-cell presents a clear uniform appearance ; but, as division 
approaches, a zone of granular substance accumulates about the nucleus, 
which the author terms the periharyoplasm. It was observed in living 
cells. When the nuclear membrane breaks down, the perikaryoplasm 
and the linin of the nucleus form a network of kinoplasm fibres. These 
grow out into several projections, and become the cones of the multipolar 
spindle. Spindle-fibres are formed by the elongation of the meshes of 
the network. The cones elongate, become sharp-pointed, and fuse in 
* Ann. Sci. Nat. (Bot.),vi. (1898) pp. 177-220 (2 pis.). Cf. this Journal, 1898, p. 205. 
t Of. this Journal, ante, p. 48. 
X Proc. California Acad. Sci., iii. (1898) pp. 109-84 (4 pis.). See Bot. Gazette, 
xxvii. (1839) p. 77. 
