Which of the following statements about osteoclasts is not TRUE?

Osteoclasts are of monocytic (hematopoietic) origin. They differ histologically from osteoblasts because they are multinucleate cells with acidophilic cytoplasm, whereas osteoblasts have basophilic cytoplasm and only one nucleus. Osteoblasts stain well with alkaline phosphatase; osteoclasts stain with acid phosphatase. Osteoclasts are found in indentations in the bone they are resorbing. These indentations are called Howship's lacunae. The cytoplasmic surface that abuts the Howship's lacuna has many projections, somewhat like microvilli, that are referred to as ruffles. Next to the ruffled border is a clear zone that delimits the outer edge of bone resorption. An electron microscopy, the only organelles found in the clear zone are actin filaments, which are thought to attach the osteoclast to bone and create a seal around the resorptive.