"art or practice of finger-spelling, use of the manual alphabet," 1650s, from chiro- "hand" + -logy "a speaking."

"the science of the skin and its diseases," 1819, from dermat- "skin" + -logy. Related: Dermatological.

"scientific study or knowledge of birds," 1670s, from Modern Latin ornithologia (1590s); see ornitho- + -logy.

"scientific study of plankton," 1892, from German planktologie (1891); see plankton + -logy. The native formation planktonology (1896) is less common.

"the science of wines, the study of the nature, qualities, and varieties of wine," 1781, from oeno- "wine" + -logy. Related: Oenological; oenologist.

"study of blood serum," 1907, from sero-, combining form of serum (q.v.), + -logy. Related: Serological; serologist.

"the science of fishes; the department of zoology which treats of fishes," 1640s, from ichthyo- "fish" + -logy. Related: Ichthyologist; ichthyological.