It is an old and common fault, that when the Greek and Roman authors have not given us such descriptions of natural objects as are sufficient to enable us to ascertain exactly what they are, we suppose that they have been known under different names, and a variety of characteristics are drawn together to enable us to determine them. What, for example, we find respecting the _cinara_ is too little to give a just idea of the plant; we read somewhat more of the _carduus_; and because between these there seems to be an affinity, it is concluded that the _cinara_ and the _carduus_ were the same plant; and everything told us respecting both of them is thrown into one. Some even go further, and add what they find under a third or a fourth name. It is indeed true, that many natural objects have had several names, and the species may sometimes be rightly guessed; but conjecture ought never to be admitted unless the identity can be fully established; else one may form such a monstrous production as Horace has delineated, when he says, Humano capiti cervicem pictor equinam Jungere si velit, et varias inducere plumas, Undique collatis membris-- I wish commentators would follow the example of our naturalists, who consider a plant as a distinct species until it has been proved on sure grounds that it is nothing else than a variety of a plant already characterized. I should not therefore affirm that the _cinara_ and the _carduus_ are the same, were I not able to produce the following incontestable proofs in support of my assertion. In the first place, the Latins, Palladius and Pliny, give us the same account of the _carduus_ that Columella and the Greeks do of the _cinara_. The former lost its prickles through cultivation[603]; its flowers were also of a purple colour[604]; it was propagated by seed and by shoots; it required frequent watering; and it was remarked that it throve better when the earth was mixed with ashes. Had not the _carduus_ and the _cinara_ been the same, Palladius and Pliny would have mentioned the latter; for we cannot suppose that they otherwise would have omitted a plant that formed a dish so much esteemed and so well-known among their countrymen. The latter claims to himself the merit of having passed over no one that was held in estimation. In the second place, Virgil has translated the word _cynaros_ in a part of Sophocles now lost, by _carduus_[605]; thirdly, Athenæus says expressly, that the _cinara_ was by the Latins named _cardus_ and _carduus_[606]; and, lastly, the old glossaries explain _cinara_ by _carduus_, as we are told by Salmasius. On these grounds, therefore, I am of opinion that the _cinara_ and the _carduus_ were the same.