And some minutely crystalline varieties, such as flint, may be opaque and of a waxy luster . 某些细小的结晶变种,如燧石,可能是不透明的,并具有腊样的光泽。
A few tests indicate that the north florida variety actually needs exposure to some cold weather . 少数试验表明,北佛罗里达变种确实需要经过某些寒冷的气候。
It harmonises perfectly with the view that there is no essential distinction between species and varieties . 这和物种与变种之间并没有本质区别的观点,却是完全符合的。
Species have not been independently created, but had descended, like varieties, from other species . 物种和变种一样,是从其它物种所传下来的,而不是分别地创造出来的。
If a variety were to flourish so as to exceed in numbers the parent species, it would then rank as the species . 如果一个变种的繁殖,超过它的亲种数量,它就会被列为物种。
If closely-allied forms or varieties are planted near each other, it is hardly possible to raise pure seedlings . 如果近缘的品种或变种种植在很相近的地方,往往难得到纯粹的种子。
If we thus argue in a circle, the fertility of all varieties produced under nature will assuredly have to be granted . 我们若依这样的循环法辩论下去,必然承认在自然状况下所产生的一切变种都是能育的了。
The difficulty in distinguishing variable species is largely due to the varieties mocking, as it were, other species of the same genus . 变异的物种所以难于区别,主要在于变种和同属中其他物种相象的缘故。
New variants of some plant viruses have been produced artificially in the laboratory by treating pure virus strains with mutagens . 用亚硝酸之类的诱变处理纯病毒株系,能在实验室内人为地使有些植物病毒产生新变种。
Each new variety or species, during the process of its formation, will generally press hardest on its nearest kindred, and tend to exterminate them . 在每一新变种或新种的形成过程中,常常对于最近缘的种类压迫最甚,并且还有消灭它们的倾向。