diff --git a/src/python/stressgrowth.cellml b/src/python/stressgrowth.cellml
new file mode 100644
index 0000000..d0575ac
--- /dev/null
+++ b/src/python/stressgrowth.cellml
@@ -0,0 +1,84 @@
+<?xml version='1.0'?>
+<!--
+This CellML file was generated on 3/04/2014 at 12:12:01 at p.m. using:
+
+COR (0.9.31.1409)
+Copyright 2002-2014 Dr Alan Garny
+http://cor.physiol.ox.ac.uk/ - cor@physiol.ox.ac.uk
+
+CellML 1.0 was used to generate this model
+http://www.cellml.org/
+-->
+<model cmeta:id="stressgrowth" name="stressgrowth" xmlns="http://www.cellml.org/cellml/1.0#" xmlns:cellml="http://www.cellml.org/cellml/1.0#" xmlns:cmeta="http://www.cellml.org/metadata/1.0#">
+    <units name="millisecond">
+        <unit prefix="milli" units="second"/>
+    </units>
+    <units name="per_millisecond">
+        <unit exponent="-1" prefix="milli" units="second"/>
+    </units>
+    <units name="stress">
+        <unit units="dimensionless"/>
+    </units>
+    <component name="Main">
+        <variable initial_value="0.000005" name="S11" units="stress"/>
+        <variable initial_value="0.000001" name="S22" units="stress"/>
+        <variable initial_value="0.0000001" name="S33" units="stress"/>
+        <variable initial_value="0.02" name="bff" units="stress"/>
+        <variable initial_value="0.015" name="bnn" units="stress"/>
+        <variable initial_value="0.001" name="bss" units="stress"/>
+        <variable name="time" units="millisecond"/>
+        <variable initial_value="1.0" name="lambda1" units="dimensionless"/>
+        <variable initial_value="1.0" name="lambda2" units="dimensionless"/>
+        <variable initial_value="1.0" name="lambda3" units="dimensionless"/>
+        <math xmlns="http://www.w3.org/1998/Math/MathML">
+            <apply>
+                <eq/>
+                <apply>
+                    <diff/>
+                    <bvar>
+                        <ci>time</ci>
+                    </bvar>
+                    <ci>lambda1</ci>
+                </apply>
+                <apply>
+                    <times/>
+                    <cn cellml:units="per_millisecond">1</cn>
+                    <ci>bff</ci>
+                    <ci>S11</ci>
+                </apply>
+            </apply>
+            <apply>
+                <eq/>
+                <apply>
+                    <diff/>
+                    <bvar>
+                        <ci>time</ci>
+                    </bvar>
+                    <ci>lambda2</ci>
+                </apply>
+                <apply>
+                    <times/>
+                    <cn cellml:units="per_millisecond">1</cn>
+                    <ci>bss</ci>
+                    <ci>S22</ci>
+                </apply>
+            </apply>
+            <apply>
+                <eq/>
+                <apply>
+                    <diff/>
+                    <bvar>
+                        <ci>time</ci>
+                    </bvar>
+                    <ci>lambda3</ci>
+                </apply>
+                <apply>
+                    <times/>
+                    <cn cellml:units="per_millisecond">1</cn>
+                    <ci>bnn</ci>
+                    <ci>S33</ci>
+                </apply>
+            </apply>
+        </math>
+    </component>
+</model>