Ethnographic work that describes how Maori patterns represent several social markers (family line, tribal affiliation, spiritual beliefs). This is a great resource for those interested in traditional Maori tattoo design.
As a researcher in the late 19th-early 20th century, Robley’s methods would today be considered illegal - it was his common practice to collect dried tattooed heads (mokomokai). Robley eventually tried to sell his study collection back to the government of New Zealand and was rightfully refused; the collection was instead purchased by the American Museum of Natural History in New York.
In the last 20 years there has been a movement towards the repatriation of human remains to the governing bodies of indigenous peoples from the museums that formerly collected them.
In 1990 the US passed the Native American Graves and Repatriation Act (NAGPRA) which required federal agencies and institutions that received federal funding to return specific classes of items (including remains) to the Native American groups that had rightful claims to them. In some cases where indigenous groups lack proper facilities to preserve their cultural property their representatives have partnered with the host museum to store their items; human remains are generally reburied. In institutions where materials are kept on behalf of indigenous groups said groups have access to their cultural property and can stipulate who can or cannot work with their items if any taboos prohibit contact. It should be noted that this act only has influence over US institutions regarding items belonging to people of indigenous cultures found within the United States; to date there is no international law mandating repatriation of human remains and other culturally-significant items to native soil.
Despite the fact that no international law requires that museums repatriate contested materials, many are doing just that to right what is seen by many as historical wrongs. In the early days of archaeology and anthropology artifacts and specimens were often gathered under murky or sometimes blatantly unethical circumstances. As these fields developed so did professional standards for field work, however the early years left museums with many collections of foggy provenance.
Cheers for The Field Museum in Chicago being progressive on the matter of international repatriation of human remains and items of cultural patrimony. I remember when the Maori visited the museum to help facilitate the process of repatriating items and remains that belonged to a specific group - it was an extremely powerful event for all who were fortunate enough to witness and take part in it. While some mokomokai have been repatriated internationally, I could not find any conclusive information on whether or not the Robley collection ever made it back home.
In 2007 the New York Times wrote a very interesting piece about the debate here:
French Debate: Is Maori Head Body Part or Art?
France approved the repatriation in question last year.