Who was David Grant Carlisle/Carlyle?

[andrew shanks]

David Grant Carlisle/Carlyle was born in Bo'ness and is recorded in the IGI as being the son of Jane Carlisle/Carlyle and John Grant.  He lived until 1978.  Here is the IGI entry for him:

David Grant Carlisle 
Male     
Event(s):
Birth:  23 JUL 1892   Bo'Ness, West Lothian, Scotland 
Christening: 
Death: 
Burial: 
Parents:
Father:  John Grant 
Mother:  Jane Carlisle 

The following information may relate to his parents & their family(ies):

Name: John GRANT
Sex: M
Birth: 3 AUG 1860 in Bo'ness, West Lothian, Scotland
Death: AFT 1926 
Occupation: 4 APR 1881 Sawyer

Marriage 1
Margaret "Maggie" MCLAREN b: 30 NOV 1869 in Bo'ness, West Lothian, Scotland
Married: 20 FEB 1891 in Bo'ness, West Lothian, Scotland 4
Children
Annie (Agnes?) Bell GRANT

Marriage 2
Jane\Jeanie Carlyle or CARLISLE b: 1870
Married: 31 DEC 1896 in Bo'ness, West Lothian, Scotland
Children
Martha Waugh GRANT b: 1897
Julia GRANT b: 1899 in Bo'ness, West Lothian, Scotland
Katie GRANT b: 26 JUN 1908 in Snab Rows, Bo'ness

But where was David?  Why did he not take the name Grant as a surname? Who exactly were his parents and was he illegitimate?

I would be grateful for any information about David Grant Carlisle/Carlyle.