562 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
spore-like bodies. At the same time similar bodies which have been 
detected within the frustules of diatoms have undoubtedly frequently been 
of a parasitic nature. 
Endochrome of Diatoms.* * * § — Mr. H. W. Shrubsole thus describes the 
changes which take place in the endochrome of Pleurosigma angulatum 
in the course of its development. At first, in the young frustule the 
endochrome is distributed uniformly in the cell without presenting any 
lacunae or solution of continuity. It divides, and appears to become 
denser in contracting, the contraction continuing until two narrow 
sometimes sinuous bands are formed, running parallel to the longitudinal 
axis of the diatom, and sometimes joining at their extremities. These 
bands then divide in the middle, and the nucleus, itself divided, appears 
to be absorbed by each of the two or of the four masses thus formed. 
At the extremities of these masses, small rounded bodies of a dark colour 
then commence to show themselves, until all the endochrome within the 
frustule has thus become broken up. A little later a thin transparent 
membrane is formed round each of these dark bodies, which detaches 
itself slightly from the margin, and this transparent protoplasm con- 
tinues to develope until a kind of lobe is produced, bearing a strong 
resemblance to an amoeba. These amoeba-like bodies then assume a 
more definite form, develope cilia, and display rapid movements. 
Whether they are in reality parasitic organisms the author leaves unde- 
termined. 
Sporulation and Division in Melosira.f — Count Abbe F. Castracane 
records another example, observed by him, of the formation of spores, 
and of fission, in two distinct forms of Melosira varians. The origin of 
a chain of frustules appears to be a spherical frustule formed from a 
spore, the chain of intermediate frustules resulting from the division of 
this one ; the series terminates, and again commences with a hemi- 
spherical valve. 
Chsetoceras, and Peragalla g. n.J — Herr F. Schiitt describes 26 new 
species of Chsetoceras, mostly from the Baltic ; also a new genus of 
diatoms, Peragalla , allied to Attlieya , and forming an interesting link 
between the Chsetocereae and the Rhizosolenieae. The structure of the 
body is that of Dadyliosolen , while the valves resemble altogether those 
of Chsetoceras. The cells have an elongated cylindrical form, with inter- 
mediate bands forming interrupted rings ; each valve is provided with 
two long hollow horns, which are themselves often spiny or thorny. 
Schmidt’s Atlas der Diatomaceen-Kunde. — Heft -50 of this work 
(Pis. 197-200) contains illustrations of the genera Cocconeis, Achnan- 
thidium , Terpsinoe , Pleurodesmium, and Anaulus. 
Structure of Cyanophyceae.§ — Prof. R. Chodat has examined the 
structure of Chroococcus turgidus, and differs in several points from the 
conclusions of Palla, Zukal, and others. The so-called “ central body ” 
* Le Diatomiste, ii. (1895) pp. 149-50. 
t Atti Accad. Pontif. Nuovi Lincei, xlviii. (1895) 4 pp. 
X Ber. Deutsch. Bot. Gesell., xiii. (1895) pp. 35-48 (2 pis.). 
§ Arch. Sci. Phys. et Nat., xxxii. (1894) pp. 637-44. Cf. this Journal, ante , 
p. 213. 
