The problem, however, remained the next level of biological intricacy: the enigmatic genes and the DNA that composed them. These were much trickier to isolate and understand. As late as 1933, when Morgan was awarded a Nobel Prize for his work, many researchers still weren't convinced that genes even existed. As Morgan noted at the time, there was no consensus "as to what the genes are — whether they are real or purely fictitious."
不过，在下一个生物学的复杂层面上，问题依然存在着，这就是有些神秘的基因及构成它们的DNA非常难于分解和研究。直到1933年底，摩尔根获得诺贝尔奖时，许多研究人员连对基因的存在都依旧表示怀疑：正如摩尔根当时所指出的那样，“基因是什么——它们是真实存在还是纯属想像”，人们很难达成一致意见。

It may seem surprising that scientists could struggle to accept the physical reality of something so fundamental to cellular activity, but as Wallace, King, and Sanders point out in Biology: The Science of Life (that rarest thing: a readable college text), we are in much the same position today with mental processes such as thought and memory. We know that we have them, of course, but we don't know what, if any, physical form they take. So it was for the longest time with genes. The idea that you could pluck one from your body and take it away for study was as absurd to many of Morgan's peers as the idea that scientists today might capture a stray thought and examine it under a microscope.
一种在细胞活动中具有如此至关重要的作用的东因，科学家们对于它的真实性总是迟迟不愿意承认，这也许是令人惊讶的。在《生物学：生命科学》（一本可读性极强的十分珍贵的大学课本）一书中，华莱士、金和桑德指出，对于思考、记忆这样的精神活动，我们今天大体上处于同样的情况。毫无疑问，我们知道我们拥有它们，但是我们不知道它们取何种具体的存在形式，如果有的话。在很长时间里基因也是如此。对于摩尔根同时代的人来说，你可以从你身上取下一个基因拿去作研究，这种想法非常荒谬，如同今天有人认为科学家可获取一束思想并在显微镜下加以检验一样。
What was certainly true was that something associated with chromosomes was directing cell replication.
当时可以肯定的是，某种与染色体相关的东西支配着细胞的繁殖。