I've already posted many cool finds from Google Books, but here is another wonderful illustration of how much information is rapidly becoming available instantly (if you know what to look for and how to look!).
There is a well known mishna (Cholin 9:6) which references an animal born through spontaneous generation:
שרץ שחצייו בשר וחצייו אדמה
Also mentioned in BT Sanhedrin 91a
עכבר שהיום חציו בשר וחציו אדמה
This is a rodent of some kind which is "half flesh and half earth." There is an abundance of literature on this, commentaries, discussions, etc. A wonderful overview by R. Natan Slifkin is here; it is also discussed in much more detail in his Mysterious Creatures.
One of the more famous comments is by R. Yisrael Lipschuetz in his commentary on the mishnah Tiferes Yisrael. It is this:
R. Slifkin already translated the relevant part, so here is his translation:
I have heard heretics mocking regarding the creature that is discussed here and in Sanhedrin 91a, and denying it, saying that there is no such thing at all. Therefore, I have seen fit to mention here that which I found written in a Western European work compiled by a scholar renowned amongst the scholars of the world. His name is Link, and the book is titled Urwelt. In Volume I, page 327, he writes that such a creature was found in Egypt in the district of Thebes, and that rodent is called, in the Egyptian language, dipus jaculus; and in the language of Ashkenaz it is called springmaus. Its forequarters – its head, chest and hands – are perfectly formed; but its hindquarters are still embedded in the earth, until after several days when it fully changes to flesh. And I say, “How great are Your works, Hashem!”
Look what Google Books does. Here is Heinrich Friedrich Link's Die Urwelt und das Alterthum from 1821.
True, you need to be able to read German (in gothic script, no less). But it took me about 10 second to find this.
(It is no matter that Dr. Shnayer Leiman showed that R. Lipschuetz misunderstood his source. However, it is worth noting that when Artscroll discusses this half flesh-half dirt mouse in its commentary to Cholin 127a they note that Tiferes Yisrael's reference is a mistake according to "modern scholars," "modern scholars" meaning "Dr. Shnayer Leiman.")
EDIT: On page 184 fn. 36 of Hellenism in Jewish Palestine,"The Natural Science of the Rabbis," R. Saul Lieberman writes: "Comp. also בועז in Mishna ed. Romm. The book referred to by the author is inaccessible to me."