Why does data from a model not render in an Ember template's {{#each}} loop?

Data that seems successfully loaded into my model does not seem to be used when rendering a page template in Ember 2.1.0. How can I get the data that is shown to me in Ember Inspector to be successfully called by the page template?

I have a model:

  App.Part = DS.Model.extend({
    name: DS.attr('string'),
    summary: DS.attr('string')
  });

  App.IndexRoute = Ember.Route.extend({  
    model: function() }
     return this.store.findAll('part')
    }
  });

and a template:

{{appName}} v {{appVersion}}
<ul>
  {{#each part in model}}
        <li>{{part.name}}</li>
    {{else}}
        none found...
  {{/each}}
</ul>

and in my Ember Inspector I see data (loaded via RESTAdapter):

But the template when rendered always says, "none found..." and never lists the data that appears to have been successfully loaded. I have tried multiple variations of the {{#each}} tag.

A standard app controller loads data into the template just fine (calling {{appName}} or {{appVersion}}):

App.ApplicationController = Ember.Controller.extend({
  appName: "My App",
  appVersion: "1.0",
});

Ember 2.1.0, EmberData 2.1.0, EmberInspector 1.9.3