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spermogonium consists of a flask-shaped body, sunk in the substance of the leaf, 
formed of exceedingly delicate threads about half the diameter of those of the 
mycelium, and originating from them (De Bary). The mouth of the flask is coni- 
cal, and, by pressure, is easily split from top to bottom into parallel fibres or 
elongated cells. The interior is filled with delicate threads which bear upon their 
ends chains of exceeding minute bodies, called spermatia. The spermatia vary a 
good deal in size and form, some are elongated, others nearly spherical; they 
measure from 2 to 3mk. by .5 to2mk. Their function has not as yet been abso- 
lutely demonstrated, but there is little doubt that they play the part of the male 
element. If I am not greatly mistaken, they are the bodies one so constantly sees 
surrounding and adherent to the spores of many species of Mcidiwm.* The ger- 
mination of ripe Alcidium-spores may be watched upon the cuticle of a wheat 
plant, and the way in which their germ-tubes squeeze into the stomata easily seen. 
EXPERIMENTS WITH AUCIDIUM-SPORES. 
On May 23rd, I infected twenty wheat plants with ripe Avcidium-spores that 
had been sent me from Drayton Rectory. These wheat plants had been carefully 
protected from accidental infection by being continuously covered with a bell- 
glass from the day they were sown until the experiment was concluded. On June 
4th, Uredo appeared upon ten of these plants. I then removed the plants to my 
study, where, day by day, the Uredo made its appearance upon fresh plants until 
the whole were affected. An equal number of wheat plants were kept as a control 
experiment ; they were protected in the same way from accidental infection, and 
remained perfectly free from Uredo the whole time. 
Concerning the barberry Mcidiwm, it only remains to add, that there are at 
least two other /cidia upon various barberries that are in no way connected with 
Puccinia graminis. One of these has only been found in Chili, where Gay met 
with it some forty years ago. It is mentioned by Montagne+as occurring in com- 
pany with a Puccinia on the leaves of Berberis glauca. De Baryt examined an 
original specimen of Montagne’s plant, and found the spores to be twice the size 
of the Puccinia graminis Acidium; and he also found the Puccinia berberidis, 
Mont., differed not only from P. graminis, but from all other European Puccinie. 
In 1875, Dr. P. Magnus§ drew attention to the occurrence, in various parts of 
Europe, of an Zcidiwm upon barberry, which was originally described under the 
name of 47. magelhanicum by Mr. Berkeley|| from specimens collected by Captain 
King at Port Famine, in the Straits of Magellan, upon Berberis ilictfolia. It 
differs from the Meidium of Puccinia graminis in appearing earlier in the year ; 
in its cups being less elongated, and in their being scattered upon the under-side 
of the leaf; in the spores being larger; and in their germ-tubes not entering the 
leaves of grasses. It is probably identical with the 4. graveolens collected by 
Shuttleworth, at Berne, in 1833, as mentioned by Dr. Cooke. 
* Plowright, in Grevillea, vol. x., p. 140, t. 159, f. 2. 3. 
+ Montagne, Syddoge, p. 314, No. 1138. 
t De Bary, éoc. czt., pp. 31, 32. 
§ Magnus, Hedwigia, vol. xv., No. 1876, p. 2. 
|| Berkeley, in Hooker’s Flora Antarctica, vol. ii., p. 450, pl. 163, fig. 2. 
Cooke, Fungi, their Nature, &c., p. 203, f. 108. 
