Sentence:  For four of the six ( the anaconda and the amethystine python cannot be included for lack of data ) there is also a correlation between size at maturity and maximum <WSD>length</WSD> , the boa constrictor being the smallest and the Indian python the next in size at the former stage . 
Meaning of the word marked with <WSD> tags:  the linear extent in space from one end to the other; the longest dimension of something that is fixed in place