The black rot of the grape (Figs. 12-15) does not ap-pear to be quite so intricate as the black knot. Two of its forms are especially important. (1) the sack spores, shown in a cavity, somewhat magnified at Fig. 14, and simply in their sacks, more magnified, at Fig. 15; (2) the stylospores, seen oozing out of their cavities, somewhat magnified, at Fig. 12, and in a section, more magnified at Fig. 13. The latter were, until recently, the only kind of spores well-known in this fungus, and are the only ones seen in great abundance. They grow on the leaves as well as the fruit, and naturally having a different appearance on the leaves, were thought to be a distinct species not particularly injurious. They were therefore disregarded, and remained a constant source of infection for the fruit.

These examples are merely familiar illustrations of thousands of similar cases, some of which have been investigated but most of which are yet but poorly known. How shall such plants be named, or if, as frequently is true, each form has its name or even several names, what shall be the name of the fungus as a whole ? To the black knot only one name was originally given, Sphaeria morbosa, and when its various kinds of spores were found, they were recognized as belonging to it and called by its name. But the different forms of black rot were at first supposed to be distinct species and they received different names. The black wheat rust was called Puccinia graminis in 1797. A little later the red rust was named Uredo linearis, being considered a distinct species; but several years earlier than either of these, the cluster-cup form on the barberry was called Aecidium Berberidis. When the red and the black rots were found to be of the same species, there was no difficulty about the name, because the older of the two names was the one that had been given to the most highly developed spores, and it is now rightfully applied to both forms; but when the cluster-cup was proved to be a form of the same fungus, the question arose, shall the law of priority be followed and the name be Puccinia Berberidis, or shall the original name of the most highly developed stage be retained ? The first name must be Puccinia, because the fungus belongs in that genus; Puccinia graminis is the name still used.

One of the other wheat rusts was first studied in its red form and called Uredo Rubigo-vera. Afterward its black spores were called Puccinia striaeformis. When they were found to be forms of the same species, the older specific name was combined with the proper generic name, and the fungus was called Puccinia Rubigo-vera ; but some claim that it should still be Puccinia striaformis.

Another question arises here. It is a necessary custom to append to a scientific name the name (often abbreviated) of the man who named the plant. Who is the author of the name Puccinia Rubigo-vera ? Some botanists claim that it is the man who gave the name Rubigo-vera, though he placed it in another genus ; others say it is the man who first put together the names Puccinia and Rubigo-vera ; still others hold that both men's names should be appended as authorities, the first in parenthesis, thus: Puccinia Rubigo-vera (De Candolle), Winter.

The black rot fungus of the grape has had more than twelve different names, applied to different stages or the same stage growing under different conditions, or by botanists in ignorance of names previously given, or by others who made too much of unimportant differences. The botanist cannot ignore these names ; he must take account of every one. If one of the variations is allowed to stand as a supposed distinct species when it is only a form of the rot, it may be ignored in applying remedies, and so remain a source of infection. This was actually the case until recently with the leaf forms of the black rot.

But having once recognized any fungus in all its forms and variations, and having selected the name which ought properly to be retained, the other names need only be recorded in a list of synonyms and laid away. The most highly developed form of this fungus was the last to be discovered, therefore the last to be named, but fortunately all have agreed in retaining the specific name of this form.

If this is all confusion to the reader, will he not feel a little pity for the botanist who is compelled to study names when he wants to study plants ?

Harvard University. A. B. Seymour.

A Race Of Flowerless Plants II The Metamorphoses O 24A Race Of Flowerless Plants II The Metamorphoses O 25

Fig. 2.

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Fig.3.

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Fig. 4.

Fig. 9.

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Fig. 10.

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Fig. 13.

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Fig. 15.