BRITISH MYCETOZOA. 



be described as masses of naked protoplasm abounding in nuclei 

 and more or less coloured granules. The nuclei at this early stage 

 appear to be those of the individual swarm-cells which have fused 

 together. Careful investigations lead to the conclusion that the vast 

 multiplication of nuclei which takes place during the growth of the 

 Plasmodium results from simple division. Apparently one instance 

 only of division by karyokinesis in this stage of the Plasmodium has 

 been recorded, and of this observation permanent preparations are pre- 

 served (Fig. 5). As the plasmodium increases in bulk by the ingestion 

 of nutritive matter and by the union of small plasmodia, it acquires 

 the remarkable streaming movement peculiar to itself. In the majority 

 of species the plasmodium is white, but there are many in which it 

 is yellow, and in some it is greenish, pink or purple. It penetrates 

 the substance of dead wood or spreads over the surface of dead 



Badhamia UTKicuLARls Berk. 



Group of nuclei from actively feeding 

 Plasmodium that covered two pilei ol 

 Auricularia in fourteen hours, show- 

 ing the irregular size of the nuclei and 

 large nucleoli. 



Stained in picro-carmine and mounted in 

 Canada balsam. Magnified 1200 times. 



Fig. 5. — Badhamia utricularis Berk. 



Division of nuclei by karyokinesis in 

 the streaming plasmodium. Magni- 

 fied i2co times. 



From a preparation stained in satianin, 

 and mounted in Canada balsam. ] 1 



leaves, bark, etc., in a network of veins, taking a somewhat fan- 

 shaped outline ; through these veins the more fluid matter in the 

 interior streams constantly in a rhythmic flow. The current con- 

 tinues in one direction for a certain period, usually a minute and 

 a half, when it stops, and after a moment's pause reverses its course, 

 flowing the opposite way for about the same length of time, but 

 rather longer in the direction in which the mass is advancing. It is 

 by this means that the plasmodium creeps forward. The object ot 

 this onward movement appears to be a search for food. If the 

 yellow plasmodium of Badhamia utricularis, which feeds on woody 

 fungi, is cultivated on Stereum hirsutum, placed on a plate and 

 covered with a glass shade, it extends itself over the fungus with a 

 turgid advancing border until it has devoured the more delicate 

 hyphas. Having exhausted the nutriment, it will spread over the 



