Comment in Dynamic HTML not honored

HTML

<script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>
<input type='checkbox' data-bind="checked:showCheck"/>Show

<div id='fixture1'>
</div>

<div id='fixture2'>
</div>

CoffeeScript

class MyClass
    constructor: ->
        @showCheck = ko.observable(false)
    loadContent: (onloaded)=>
        content1 = "<!--ko if: showCheck -->fixture 1 is here<!-- /ko -->"
        content2 = "<div data-bind='if: showCheck'>fixture 2 is here</div>"
        debugger
        $('#fixture1').append(content1)
        ko.applyBindings(@,$('#fixture1')[0])
        $('#fixture2').append(content2)
        ko.applyBindings(@,$('#fixture2')[0])
        onloaded() if onloaded?
        
window.thisClass = new MyClass()
ko.applyBindings(window.thisClass)

setTimeout =>
    window.thisClass.loadContent  =>
        $('body').append('loaded!')
, 1000