312 XXIII. REPRODUCTION OF FUNGI. 



of yellowish- brown protoplasm. In the youngest stages the 

 gonidiophore is not cut off from the gonidangium ; later on there 

 arises a partition wall, strongly arching into the interior of the 

 gonidangium, so that the stalk ends within this latter with a 

 swelling like a ninepin, the so-called columella. The ripe gonid- 

 angium deliquesces in water, and of its wall only fragments 

 formed of fine needles remain behind, of which it has been 

 determined that they consist of oxalate of lime. The expelled 

 gonidia lie at fairly regular distances from one another, and 

 by pressure on the cover-glass we can determine that they lie 

 embedded in a colourless mucilage. On the stalk, under the 

 columella, is usually to be seen a small collar, a relic of the lime 

 crust which was attached there. In the protoplasmic lining 

 layer of stalks which are not too old, we can follow fine, usually 

 longitudinal, streaming of the protoplasm. The sacs of Mucor 

 are multinuclear, the nuclei very small, only distinguishable 

 by suitable fixing and staining. 



If uninjured material be transferred to absolute alcohol, 

 chromic acid, or picric acid, and afterwards stained, the lining 

 plasmic layer of the mycelium, as of the aerial gonidiophores, 

 can be seen to contain numerous small nuclei, scattered at 

 irregular distances, and connected together by plasmic threads. 

 They are also recognisable in the gonidangia, and, though with 

 more difficulty, in the gonidia. The best treatment for Fungi 

 is to fix with weak Flemming's solution, and stain with saffranin, 

 gentian-violet, or orange. In most cases the saffranin should act 

 for half an hour, the gentian-violet for fifteen minutes, the orange 

 for only a very short time. The preparation should then be 

 rapidly washed with alcohol and oil of cloves. 



Slide Culture of Mucor. Mucor Mucedo is a very suitable 

 object wherewith to be introduced to the methods of fungus 

 culture upon the object-slide, and we will therefore amplify here 

 the methods already learned in connection with bacteria and 

 yeast. We prepare, when needed, a suitable culture-fluid, by 

 boiling horse-dung in water. The infusion is filtered clear, and 

 then again boiled for a long time in order to sterilise it. The 

 object-slides and glass-utensils needed for use must likewise be 

 sterilised by passing through a gas or spirit flame, or by being 

 laid for a short time in absolute alcohol and then in ether, which 

 latter will rapidly evaporate after removal. It has also been 

 recommended to preserve the glass-utensils in 10 per cent. 



