374 ON THE STUDY OF MICRO-FUNGI. 



of the spore to the distant end of the tube. The tube will become 

 branched, and, if the spore be upon a leaf of the Lapsana, it will 

 find its way through one of the stomata into the tissues, and there 

 grow and give rise to another mycelium. These germinating 

 uredospores may be placed upon other plants than the Lapsana — 

 as, e.g.^ the Daisy and Nettle again — but they will produce no myce- 

 lium in them. In this new mycelium fresh spore beds will soon 

 be formed, and hyphai given off as before in the direction of the 

 surface of the leaf. These hyphae become expanded at the upper 

 ends into oblong spores, or rather compound spores, for a trans- 

 verse division in the centre of each of these oblong spores divides 

 it into two chambers, thus practically making two spores, one above 

 the other. These are called the teleutospores ; that is, the last 

 spores which are produced. The teleutospores in many species 

 have only one cell or compartment, but in the present species they 

 have, as already stated, two cells, and are known by the distin- 

 guishing name of Fuccifiia. They will be found probably from 

 May to August, and will appear sprinkled over both surfaces of 

 the leaves in black or dark brown Httle spots. 



We have seen that as soon as the aecidiospores and uredospores 

 were ripe, they germinated at once on being placed in water ; but 

 the teleutospores that we are now considering do not germinate 

 until spring of the following year. Throughout the winter months 

 they remain unchanged and exhibit no signs of life ; but after this 

 period of rest is over, and when the season once more comes 

 round for the Lapsana to put forth its young leaves, they are ready 

 to germinate. The process is somewhat different from the germi- 

 nation of the previous spores. Soon after moisture is applied to a 

 teleutospore two tubes are emitted, called promycelial tubes, one 

 from each compartment. The protoplasm passes out of the spore 

 to the far end of the promycelial tubes, where the tubes presently 

 become divided off into several compartments. From each com- 

 partment a fine short branch arises, along which the protoplasm 

 flows and accumulates at the end of it in a small, round body, 

 which is there formed, called a promycelial spore (see PI. XVIL, 

 Fig. 4). In a short time this promycelial spore drops off, and then 

 germinates by emitting a short germ-tube (see Fig. 5). This germ- 

 tube, when upon a leaf of the Lapsana, pierces through the epi- 



