Chapter IX: Gonium

Vermis inconspicuus, simplicissimus, complanatus, angulatus. An invisible, simple, smooth, angular worm.

114. GONIUM PECTORALE. G. quadrangulare, pellucidum moleculis sedecim sphæricis. Plate XXV. Fig. 17. This gonium is quadrangular, pellucid, with sixteen spherical molecules.

These sixteen little oval bodies are nearly equal in size, of a greenish colour, pellucid, and set in a quadrangular membrane, like the jewels in the breast-plate of the high-priest, reflecting light on both sides. Its animality is evinced by its spontaneous motion, advancing alternately towards the right and left; these little bodies seem oval when in motion, round when at rest; the four interior ones are a little larger than the rest. It is found in pure water.

115. GONIUM PULVINATUM. G. quadrangulare, opacum pulvillis quatuor. Quadrangular, opake, with four little pillows.

This appears like a little quadrangular membrane, plain on both sides; with a large magnifier it looks like a bolster, formed of three or four cylindric pillows, flattened or sunk here and there. Thus it appeared to Müller on the first examination; some days after all the sides were plain, without any convexity, and divided into little square spaces by lines crossing each other. It is found upon dunghills.

116. GONIUM CORRUGATUM. G. quadrangulare, albidum, medio correptum. Quadrangular gonium, white, sunk a little in the middle.

It is somewhat of a square shape, very minute, without any visible viscera, a little depressed in the middle. It is found in various infusions; in some positions it appears streaked.

117. GONIUM RECTANGULUM. G. rectangulum, dorso arcuato. This gonium is rectangular, the hind-part arched.

This differs but little from the preceding; the angle at the base is a right one, the larger vesicle is transparent, the rest green.

118. GONIUM TRUNCATUM. G. obtusangulum, postice arcuatum. Gonium with obtuse corners, the hind-part arched.

Much larger than the foregoing, the fore-part is a straight line, with which the sides form obtuse angles, the ends of the sides being united by a curved line; the internal molecules are of a dark green, there are two little bright vesicles in the middle; its motion is languid. It is found chiefly in pure water, and that but seldom.