Charles Darwin's seminal text "On the Origin of Species" was published on 24 November 1859. Charles Lyell had greatly influenced Darwin, as Robert FitzRoy gifted him a copy of Lyell's "Principle of Geology" before Darwin embarked on his five-year voyage aboard and Lyell wrote personally to Darwin in April 1843 to announce his findings on the expedition with Abraham Gesner. Darwin built a considerable amount of his theory regarding natural selection and evolution on Lyell's 1852 study of the Joggins Formation, noting that the incompleteness of the fossil record at Joggins was responsible for gaps in Darwin's theory and saying this incompleteness had contributed to a misconception of "abrupt, though perhaps very slight, changes of form". Lyell helped publish Darwin's theories, but did not support them as natural selection conflicted with his religious beliefs. In 1863, John W. Dawson published "Air-Breathers of the Coal Period", both a catalogue of all known species from the Joggins Formation at the time and a response to "On the Origin of Species". Dawson argued that the presence of fossils like "Dedropupa" (which he'd first reported on in 1860) disproved Darwin's theory, as this land snail was virtually identical to its modern counterparts, and thus the body plan of snails had not changed in 300 million years. Dawson's disbelief in natural selection was not based in religious concerns, as he did believe in deep time and the notion that higher forms of life had appeared progressively and at different periods in Earth's history; in 1865 he would argue that "Eozoon canadense" represented the earliest form of life. Samuel Wilberforce had also referenced "Dedropupa" in his 1860 criticism of "On the Origin of Species", calling it the "miserable little dendropupa".