NOTES AND MEMOEANDA. 447 



formation of the gonicUa of CMorococcum into colourless monads, and 

 be considers that the " Secretkornchen " of such flagellates as 

 Anisonema are the homologues of the still gonidia of Chlorococcum. 

 When the Anisonemce were placed in the dark, the green granules 

 became colourless, and then resembled ordinary fungus spores. 



4. In a similar chamber colourless monads, probably undeveloped 

 Anisonemce, were observed to send out mycelial filaments, which after- 

 wards broke up into short pieces ; these subsequently assumed an oval 

 form. 



5. Aspergillus spores were sown, in water, on the bottom of a 

 shallow chamber, and exposed to light. These spores became 

 brighter and quite colourless ; then, after three or four weeks their 

 contents became granular, and a nucleus-like body appeared : the cell- 

 wall at the same time became mucilaginous and the spores assumed 

 an oval form. They then divided in the direction of their length 

 into two parts. If the water evaporated somewhat, the spores 

 elongated still more, becoming spindle-shaped ; the division planes 

 became more oblique, and, in each spore, a second division-plane 

 appeared, intersecting the first, so that the two planes, as seen under 

 the Microscope, crossed one another like the two arms of an X. The 

 spores thus became divided into four elongated bodies, and thus closely 

 resembled the alga Scenedesmus. Other spores became dark green in 

 colour, and divided into four, like Pandorina. 



6. Aspergillus spores, sown in water, became colourless, their cell- 

 wall dissolved, and they became transformed into amoebiform masses, 

 and then into true Amoehce of light greenish colour. These Amoehce, 

 later, contracted into darker green spheres which divided, forming 

 motile green bodies quite like the unicellular alga Chlamydomonas. 

 In other cases the contents of the spores divided into colourless 

 granules, the spores then resembling the cysts of certain monads. 



The author concludes with some general observations on these 

 very startling results. 



Influence of Light on the Movements of Mobile Spores.— Along 

 with the movements of mobile spores, caused by currents of water, 

 which Sachs has succeeded in imitating by emulsions ('Flora,' 1876, 

 Nos. 16-18), by which spores placed in water congregate near the 

 edges of the vessel, and form the figures which Nageli has shown, zoo- 

 spores also possess, through their own innate force, a movement at 

 once progressive and rotatory. Eesearches recently made by E. Stahl * 

 have convinced him that the direction of the forward movement is 

 determined by light, and is absolutely independent of the passive 

 currents of water above mentioned. 



The following are given by Stahl as the principal results of his 

 researches, which he intends to amplify later. 



Light exercises an influence on the forward movement of many 

 mobile spores which have been called heliotropic spores. Other zoo- 

 spores are absolutely indifferent to light. 



The movement of heliotropic zoospores changes periodically in 



* ' Bot. Zeit.,' xxxvi. (1878) 715. 



