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From: martillo@ihuxt.UUCP (Yehoyaqim Martillo)
Newsgroups: net.startrek
Subject: Re: Klingon Appearances; apparent deviation
Message-ID: <505@ihuxt.UUCP>
Date: Fri, 18-May-84 13:17:15 EDT
Article-I.D.: ihuxt.505
Posted: Fri May 18 13:17:15 1984
Date-Received: Sat, 19-May-84 07:02:36 EDT
References: <153@tellab1.UUCP>
Organization: AT&T Bell Labs, Naperville, IL
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John Ford's The Final Reflection gives an explanation.

Klingon practice an immense amount of species fusion.  A lot of the
Klingon's are Klingon/Human Klingon/Romulan Klingon/Orionan etc fusions. 
The bumpy Klingons are members of the original imperial race.