Hayflick's book "How and Why We Age" is an excellent, first hand account on the research that has been conducted up to now on the biology of aging. It is of note that Hayflick is one of the pioneers in the field. The book is well written and can be enjoyed both by the scientist and the layperson. One flaw, in my opinion, involves Hayflick's personal- and highly biassed- account of the supposedly erroneous conclusions of Alexis Carrel regarding the immortality of cells cultured in vitro. After presenting what seems conclusive evidence opposing Carrel's claim, Hayflick describes a conversation with a technician who worked at Carrel's lab in New York in the thirties, who discloses highly questionable procedures, and describes threats to her when she reaised issues with the lab directors. It is clearly suggested that there was scientific negligence and even misconduct, and yet, the identity of this technician is not revealed, and the accusations, half a century la! ter, are foggy and impossible to challenge. This is a very serious issue, as Hayflick himself claims to have proven Carrel wrong, through his discovery of a fixed maximum number of divisions in cells grown in vitro. However, some even more recent experiments suggest that it is Hayflick who is wrong, because the cell culture conditions he uses are highly artificial, while Carrel's more primitive, but also more robust method (cultivating a chunk of tissue) are closer to physiological conditions. The issue at stakes is by no means trivial: are cells intrinsically immortal, ageless, or do they age and die like whole organisms?