The Mikrokosmos ontology has grown rapidly over the last six months. We started with an older ontology developed in earlier KBMT projects at Carnegie Mellon University (Carlson and Nirenburg, 1990). This had about 2000 concepts, many of which were either irrelevant to our domain or were not really concepts (such as for example, some instances that were encoded as concepts). We started an initial acquisition phase and added about 700 concepts. In the next stage, we did a thorough cleaning up (``Spring cleaning'') of the entire ontology during which time we deleted over 500 concepts. After that we more than doubled the size of the ontology to about 4300 concepts. At the present time, the ontology covers all concepts needed to represent the meanings of Spanish words collected from a 400-text corpus of newswire articles on company mergers and acquisitions. As such, we have temporarily stopped further concept acquisition and are focusing our attention on purifying the ontology to further improve the content and quality of the ontology. The graph below shows the rate of growth of the Mikrokosmos ontology.