Read this paragraph and answer the questions that follow.

Indians spoke of hibernation as the Long Sleep, but it is rather more than that. It is a profound oblivion halfway between sleep and death. It is an unknowing and unfeeling more deep and lasting than can be induced in man by the most powerful drugs, a suspension of life processes more thorough and protracted than even the "frozen slumber" which doctors have lately devised as a palliative of cancer. It is a phenomenon unique in nature, and though we are wiser about it than we were in those cradle-days of biology when Dr. Johnson thought that swallows [a kind of bird] passed the winter asleep in the mud at the bottom of the Thames, it remains a riddle still.

--Alan Devoe, "The Animals Sleep"

1			Write three content phrases from the paragraph (not transitions) that helped you arrive at your answer for question 3.
2			Explain what the writer means by the phrase "those cradle-days of biology."