Translation of the original German introduction by Ernst Haeckel:
Division of Protophyta: - class of Algaria; - subclass of Diatomea.
Diatomea or Schachtellinge form a diverse class of mono-cellular protophyta that live in large quantities in sweet water as well as in the ocean; more than 2000 species are known. Compared to other Protophytes they are characterized by the formation of a delicate, double-flapped silicic shell; both sides or flaps of the shell act like a case and its lid. The upper, slightly bigger half, the cover flap, takes hold of the border of the lower, bigger half, the case flap, with the help of a broad border, the belt. Therefore each shell has two very different aspects, the parallel (horizontal) base- or master side (fig. 1, 4 etc.) and the ring-shaped (vertical) belt- or subsidiary side (fig. 20, 21). The former usually shows a very delicate sculpture: ribs, crest, fields, grains etc. It is perforated by very minute pores. Most Diatomea are very small, they hover freely in the water and form an important component of plankton; other species are fixed to the ground with the help of gelatinous shafts.
Many species form Coenobia or cell unions with daughter cells that develop through division remaining connected.
All species illustrated on this plate belong to the solitary living (Monobia) and free swimming [Diatomea]. Most often their shells show a consistently geometrical basic form: two-sided (fig. 2, 3, 10), broadly emanating (fig. 1, 4, 22), four-jetted (fig. 7, 9, 11), five-jetted (fig. 5), multi-jetted (fig. 16). The living, soft cell body that is embed in the shell (fig. 15) contains a cell nucleus in the centre; brachiate plasma columns emanate from the delicate plasma layer that surrounds it, exhibiting the flowing movement of the living cell substance. Many Chromatella or pigments lie dispersed in the plasma net (Plasmanetz); its green colour (Chlorophyll) is usually covered by a yellow or brown colourant (Diatomin).
Translation by VR Translators Bangalore
We've scanned the original lithography at 1200dpi on the Epson A3 scanner of A3 scanner huren. You can download a 400dpi JPEG here.