6 T. THORELL, 
This last case it is especially important to take notice of, for a consider- 
able time frequently elapses between the day, when a paper is thus deliver- 
ed, and that, on which it is made accessible in print to the public; neither 
ought it to be forgotten that printed works often bear upon their title-page 
a date different from that, at which they really appeared, and which accor- 
dingly ought to stand there. — If a name has been published without caracte- 
rization, and this latter be supplied in a subsequent work, the name should 
be considered as originating at the epoch of this latter and not at that of 
the former work.!) 
Another question requiring an answer is the following: How far back- 
ward in time ought the application of the law of priority to be extended? — 
Here it would seem that a difference ought to be made according as the 
question regards the name of a genus, or that of a species, and the pri- 
ority of generic and specific names to be decided independently of each 
other. Firstly and principally as regards the names of species, it will 
probably without difficulty be admitted, that, since the Linnean binominal 
nomenclature for all species both in the vegetable and animal king. 
doms is that which is universally received, the introduction of that nomen- 
clature into science ought to constitute the epoch, from which priority should 
be reckoned, at least in the case of specific names. The præ-Linnæan 
authors, as is well known, distinguished the different species of a genus, 
not by a "nomen triviale”, as LINNÉ calls the specific names consisting of a 
single word, which he introduced, but by a brief diagnosis, "nomen specificum" 
or "differentia specifica”, which generally consisted of several words, though 
occasionally it might be comprised in but one, and in this latter case as- 
sumes to the eye the appearance of a nomen triviale. Some modern writers 
occasionally go back to these præ-Linnæan denominations, and receive the 
differenti specificæ that consist of a single word, or even the first word 
even until the last sheet leaves the press. We object to both alternatives, that no 
one is bound to know of a work as long as it, either as manuscript or even as prin- 
ted, lies concealed in the author's, publisher's, or any learned society’s stores. When 
it has been made accessible to the public in general, then, and not previously, can it 
be said to have been published. Many disagreeable controversies concerning the 
right of priority might be avoided, if it were the general custom to register consci- 
entiously upon every work the day on which it was offered to the public in the book- 
sellers’ shops, or, in cases where no exposure for sale takes place, when the distri- 
bution of the work was effected by some other process. 
1) According to this rule some of the species-names used by WALCKENAER in 
his Tableau des Aranéides (1805) will have to give place to others, published at a 
subsequent period. 
