I took a look at the IGI and the Philip Mark I saw who was baptised on 7 May 1848 was listed as being the son of Henry and Loveday Mark. On the 1871 census for Canada there is the following family in McGillivray, Middlesex County, Ontario:
Henry Mark, 70, farmer, born England
Lovedy Mark, 70, born England
Jeseph Mark, 11, born Ontario
Charles Mark, 9, born Ontario
Philip Mark, 7, born Ontario
Philip Mark, 25, farmer, born Ontario (the birthplace was likely a mistake by the enumerator)
After a little looking I found the family listed as Marks in McGillivray, Huron County, Ontario in 1861:
Henry Marks, 60, farmer, born England
Loveday Marks, 60, born England
Thomas Marks, 30, labourer, born England
Henry Marks, 25, labourer, born England
Richard Marks, 20, labourer, born England
Joseph Marks, 19, labourer, born England
Henry Marks, 17, labourer, born England
Philip Marks, 15, labourer, born England
Loveday Marks, 12, born England
The ages for Henry and Loveday don't match up with the 1841 England census but the older children's names and ages do. I can't find the family on the England or Canada census in 1851.
There's a death in McGillivray, Middlesex County for Henry Mark (81) on 18 Aug 1882 which indicates he was born in Cornwall, England. Edward Mark was the informant. Lovedy Mark died 2 Sep 1891 also in McGillivray, Middlesex County. She was 91 years 6 months old when she died. It only gives her birth place as England. Henry Mark was the informant.
Jacquie