What is an aggregate pear?

I'm reading a diary written in 1862 by a British naval officer, and he mentions stopping in Acapulco, where "Fruit is plentiful here such as bananas, water melon and the aggregate pear." I've heard avocados called alligator pears, but I can find no reference to anything called an aggregate pear. Might it be something like a pineapple, which is slightly pear shaped and could possibly fall under the definition of aggregate?