Leucocytes are colourless due to
a)	Lack of water	b)	Lack of haemoglobin
c)	Presence of extra water	d)	Presence of haemoglobin

(b)

Leucocytes or white blood corpuscles which are without haemoglobin and therefore, they are colourless and considerably larger than RBC. The normal WBC count is 6000-8000 per cubin mm of blood. Lower count is called leukopenia and high WBC count is termed as leukaemia or leucocytosis. The life span of WBC in man is about 10-30 days