diff --git a/graviton.js b/graviton.js
index ca572f3..6b12fd6 100644
--- a/graviton.js
+++ b/graviton.js
@@ -3,23 +3,21 @@ var global = this;
 var Relation = function(model, config) {
   config = config || {};
   this._model = model;
-  this._klass = config.klass;
+  this._klass = Model._klasses[config.klass];
   this._field = config.field;
   this._foreignKey = config.foreignKey;
 };
 Relation.prototype.constructor = Relation;
-Relation.prototype.klass = function() {
-  return Model[this._klass];
-};
+
 Relation.prototype.build = function(obj) {
   if (obj instanceof Model) return obj;
-  return this.klass().build(obj); 
-}; 
+  return this._klass.build(obj); 
+};
 // inserts model if it doesn't have an id - typically called by add
 Relation.prototype.persist = function(model) {
   model = this.build(model);
   if (!model._id) {
-    model._id = this.klass().insert(model.attributes);
+    model._id = this._klass.insert(model.attributes);
     model.set('_id', model._id);
   }
   return model;
@@ -33,11 +31,11 @@ ManyRelation.prototype = Object.create(Relation.prototype);
 ManyRelation.prototype.constructor = ManyRelation;
 
 ManyRelation.prototype.find = function(query) {
-  return this.klass().find(_.extend(query || {}, this._filter()));
+  return this._klass.find(_.extend(query || {}, this._filter()));
 };
 
 ManyRelation.prototype.findOne = function(query) {
-  return this.klass().findOne(_.extend(query || {}, this._filter()));
+  return this._klass.findOne(_.extend(query || {}, this._filter()));
 };
 
 ManyRelation.prototype.plain = function() {
@@ -114,7 +112,7 @@ HasMany.prototype.add = function(model) {
 
   var set = {$set: {}};
   set['$set'][this._foreignKey] = this._model._id;
-  this.klass().update(model._id, set);
+  this._klass.update(model._id, set);
 };
 
 
@@ -123,7 +121,7 @@ HasMany.prototype.add = function(model) {
 var belongsTo = function(model, config, name) {
   var rel = new Relation(model, config);
   return function() {
-    return rel.klass().findOne(rel._model.get(rel._field));
+    return rel._klass.findOne(rel._model.get(rel._field));
   };
 };
 
@@ -132,7 +130,7 @@ var embeds = function(model, config, name) {
     var obj = model.get(name);
     if (!obj) return;
     var rel = new Relation(model, config);
-    var subModel = rel.klass().build(obj);
+    var subModel = rel._klass.build(obj);
     subModel._parent = model;
     return subModel;
   };
@@ -161,7 +159,7 @@ EmbeddedModels.prototype.plain = ManyRelation.prototype.plain;
 EmbeddedModels.prototype.all = function() {
   var self = this;
   return _.map(this._objects(), function(obj) {
-    var subModel = self.klass().build(obj);
+    var subModel = self._klass.build(obj);
     subModel._parent = self._model;
     return subModel;
   });
@@ -176,7 +174,7 @@ EmbeddedModels.prototype._objects = function() {
 EmbeddedModels.prototype.at = function(index) {
   var obj = this._objects()[index];
   if (!obj) return;
-  return this.klass().build(obj);
+  return this._klass.build(obj);
 };
 
 
@@ -185,7 +183,9 @@ Model = function(klass, obj, options) {
   options = options || {};
   this.attributes = obj;
 
-  this._klass = klass;
+  this._klass = Model._klasses[klass];
+
+  if (_.isUndefined(this._klass)) throw "Can't find klass '"+klass+"' in:"+JSON.stringify(Model._klasses, null, 2);
 
   if (_.isFunction(options.initialize)) {
     options.initialize.call(this, obj);
@@ -242,13 +242,21 @@ Model.setProperty = function(obj, key, val) {
 
 // use this to declare new models
 // options contain the relations etc.
-Model.define = function(collectionName, options) {
+Model.define = function(klass, options) {
+
+  _.defaults(options, {
+    persist: true
+  });
+
+  
 
   var model = function(obj) {
-    return new Model(collection, obj, options);
+    return new Model(klass, obj, options);
   };
 
-  var collection = new Meteor.Collection(collectionName, {
+  var colName = (options.persist) ? klass : null;
+
+  var collection = new Meteor.Collection(colName, {
     transform: model
   });
 
@@ -265,6 +273,8 @@ Model.define = function(collectionName, options) {
 
   collection.build = model;
 
+  this._klasses[klass] = collection;
+
   return collection;
 };
 
diff --git a/test/graviton-test.js b/test/graviton-test.js
index d79f16d..a7062a5 100644
--- a/test/graviton-test.js
+++ b/test/graviton-test.js
@@ -25,25 +25,24 @@ Car = Model.Car = Model.define("cars", {
   },
   hasMany: {
     wheels: {
-      klass: 'Wheel',
+      klass: 'wheels',
       foreignKey: 'carId'
     }
   },
   belongsToMany: {
     drivers: {
-      klass: 'Driver',
-      field: 'driverIds',
-      cls: Driver
+      klass: 'drivers',
+      field: 'driverIds'
     }
   },
   embeds: {
     plate: {
-      klass: 'Plate'
+      klass: 'plates'
     }
   },
   embedsMany: {
     windows: {
-      klass: 'Window'
+      klass: 'windows'
     }
   }
 });
@@ -55,7 +54,7 @@ Wheel = Model.Wheel = Model.define("wheels", {
   },
   belongsTo: {
     car: {
-      klass: 'Car',
+      klass: 'cars',
       field: 'carId'
     }
   }
@@ -65,19 +64,19 @@ init(Wheel);
 Driver = Model.Driver = Model.define("drivers", {
   hasMany: {
     cars: {
-      klass: 'Car',
+      klass: 'cars',
       foreignKey: 'driverIds'
     }
   }
 });
 init(Driver);
 
-Plate = Model.Plate = Model.define(null, {
-
+Plate = Model.Plate = Model.define("plates", {
+  persist: false // sends null as mongo collection name to Meteor.Collection
 });
 
-Window = Model.Window = Model.define(null, {
-
+Window = Model.Window = Model.define("windows", {
+  persist: false
 });
 
 
@@ -132,7 +131,7 @@ Tinytest.add('Model - save', function(test) {
 });
 
 Tinytest.add('Relations - hasMany', function(test) {
-  test.equal(c.wheels.klass()._name, 'wheels');
+  test.equal(c.wheels._klass._name, 'wheels');
   test.equal(c.wheels.find().count(), 4);
   test.equal(c.wheels.all().length, c.wheels.find().count());
   test.equal(c.wheels.find({tread: 'new'}).count(), 3);